Multiplication Methods A collection of some methods for doing multiplication that have been devised and used in previous times. Notes on Multiplication Methods ~ 1 All of the methods given here are written methods. For an additional account of some mechanical methods see under 'Artifacts for Mathematics' (in the trol menu) where the material for making, together with instructions for using: Napier's Rods, Genaille's Rods and a Slide Rule, are to be found. At the back of this unit are some sheets of multiplication tables. The first is simply eight copies of a basic 1 to 9 multiplication square, which makes it easy to provide everyone with their own personal copy when those facts are needed. Needing to “know their tables” should not be made an issue in this work. The second, ‘A Book of Multiplication Tables’ is much more complicated to make. First of all it requires some care with the double-sided photocopying needed. Check that the crosses in the middle of the two sheets match (within 2 mm if possible), and also that the 94× table does back the 89× table (and NOT the 65×). The sheet has then to be folded in half three times. Do not rush this stage. Press the folds down well with some hard object (ruler or pen). The dotted lines are only a guide, the important thing is to match up the edges of the paper each time, and see that the dotted lines are on the inside of the fold. The titled front cover should always be on the outside of the fold. A staple through the last fold (the hinged edge) and three cuts along the outer edges with a guillotine will complete the process. It is nowhere near as difficult as it sounds! An alternative cover for the booklet is provided. This will have to be cut and pasted onto the master copy before the photocopying is done. All of this would only be worthwhile if the tables might be used in some other work. These same tables are also available in a straight sheet format if wanted. They can be found in the ‘Division’ unit (in the trol menu). It must be emphasied that there are many more ways of doing multiplication than those given here, though most of them are merely variations on a general theme. The ones suggested in this unit are those considered to offer the most useful insights into the historic development of this particular piece of arithmetic so some might appreciate that “No, it hasn’t always been like that!” Exactly how any or all of this material is used will be, as always, a matter for individual teachers to decide and plan for. It can be surprising to see the lengths to which mathematicians and other professional users of mathematics have gone to over the centuries to simplify the multiplication process. But remember that even so great a mathematician as Leibnitz (1646 to 1716) who invented the calculus said “It is unworthy of excellent men to lose hours like slaves in the labour of calculation.” (A feeling which many of our pupils share!) © Frank Tapson 2004 [trolFG:2] Notes on Multiplication Methods ~ 2 Using Doubling and Halving 1. The Ancient Egyptian Method This is probably the oldest of all the written methods. It is of some interest because of its links with the binary form of a number, and also because of the simplicity of the idea - it needs only an ability to be able to multiply by 2 and add. However it should also be appreciated that in those days (1000 BC or so) such things were not for 'ordinary folk' who would have had no need of such a skill. It was very much the preserve of professionals such as astrologers, architects and mathematicians. 2. The Russian Peasant Method This method was more widely used than its name might imply. It was in fact taught and practised throughout Europe for quite some time. It is a less demanding algorithm than the previous one since the numbers to be crossed off are easier to identify. It is interesting to write them side by side and see how they are doing the same thing. The link of course is the binary system underlying both. 1 2 4 8 16 32 43 268 536 1072 2144 4288 8576 11524 43 21 10 5 2 1 268 536 1072 2144 4288 8576 11524 Using the Gelosia Method (Pronounced jee - low - see - uh) 2 Any analysis or explanation of why this method works is probably best linked to looking at the place values of the different figures involved. 6 8 The worked example from the sheet is shown on the right. 2 4 1 It is easy to extend the diagram to cover tens of thousands and upwards or, tenths, hundredths, thousandths and so on downwards, and thus show why placing the decimal point works as it does. 8 H T Th Th 4 4 3 × H H H H 2 U T T U U T T This method almost certainly originated in India, as did so much of our arithmetic. From there it spread outwards to China, Persia and the Arab world. It reached Europe through Italy where it first appeared in the 14th century. The name 'gelosia' was given to it in Italy since the necessary grid resembled the lattices or gratings (= gelosia) which were made in metal and fastened in front of the windows of the houses for security. It has been claimed that Napier got the idea for his rods from this method. Whether or not he did, the possibility can clearly be seen. In fact, multiplication tables and a knowledge of place value could be dispensed with by using the two methods together. Once the grid has been drawn, a set of Napier's Rods would provide all the needed answers to complete it, and the final addition would be the only arithmetic necessary. One practical point. Do not slow things up by drawing precisely ruled grids. It is quite sufficient to write down the two numbers (adequately spaced) and sketch the grid around them free-hand. © Frank Tapson 2004 [trolFG:3] 3 2 6 The lower diagram replaces each of the the figures in the top diagram with its place value, using the usual notation of H T U, with the addition of Th for thousands. The neat way each place value falls into line along the diagonals makes it very clear why the method works. It also makes it very apparent why zeros must be included in the numbers when necessary. × 8 Notes on Multiplication Methods ~ 3 Using Quarter Squares The reason why this method works can only be justified by the use of algebra. It can be shown that (a + b) 2 ab ≡ 4 (a – b) 2 – 4 Given a and b are the two numbers to be multiplied together, and the two terms on the right are quarter squares (as defined on the sheet) then the algorithm follows from the above identity. And (provided the requisite tables are available) multiplication has been replaced by one addition and two subtractions without need for any multiplication facts to be known or found. In passing it is of interest to consider (and prove) why the remainder can be disregarded. Note that this method is completely accurate in giving all the figures possible in the final answer. Its big limitations are that (a) a set of tables is needed and, (b) the size of the numbers it can handle is constrained by the size of the tables (which has to cover the sum of the two numbers being multiplied). The second limitation is not too bad. The sample sheet included here goes to 600, so it is easy to visualize the smallish book which would be needed to reach 100,000. That means an accuracy of 4 significant figures (or better) which should cover most practical needs. Approximations allow the tables to be used for larger numbers. The method was used (but how widely is not known) and the necessary tables to enable this were published in the late 1800’s. Using Logarithms This is a much simplified version of what was once taught in the classrooms of every secondary school. The words ‘characteristic’ and ‘mantissa’ do not appear, and only numbers greater than 1 are dealt with to avoid that very troublesome negative characteristic. Also only 3-figure tables are used and the customary difference table does not appear. However, the essentials required to give a glimpse of what was done are there. In modern terms this could be called “Logarithms Lite”. The characteristic which is so necessary to control the place value has been replaced here by the e-notation. This is the notation introduced by the IEEE (= Institute of Electrical and Electronic Engineers) and used in all computer work. Gaining an acquaintance with this notation might be regarded as a valuable by-product of this piece of work. One of the inadequancies of 3-figure tables is very apparent once the numbers go beyond 5.0 when many of the logarithmic values are repeated. This cannot be avoided without moving on to 4 or 5-figure tables. Sheet 1 does not require any knowledge of the characteristic as the examples are chosen so as not to go beyond the range of the table. Also there are no ambiguous values for the logarithms. Sheet 2 introduces the idea of the e-notation. Some help might be needed with the business of using the tables, first in finding the logarithm from the number, and then the much more difficult matter of reversing that process. Further work could be done with numbers less than 1 and division. © Frank Tapson 2004 [trolFG:4] Notes on Multiplication Methods ~ 4 Using Triangle Numbers This method has the big advantage that it can be easily explained or justified diagrammatically, without any recourse to algebra, except for the generalisation at the end. For this purpose it is better to change the conventionally drawn triangle numbers (as equilateral triangles) into rightangled triangles. The appropriate drawing for T4 is shown on the right. We will do the sum 8 × 3 using five diagrams. 1. 2. 3. The sum 8 × 3 requires the number of objects making this rectangle to be counted. First make the triangle number which matches the longest edge. In this case it is T8 Cut away the triangle (shown in black) which is above the size of the rectangle. In this case it is T5 8 5 3 3 8 8 8 5. 4. Triangle removed was T5 or T (8 - 3) leaving this incomplete rectangle Complete the rectangle with smallest possible triangle (shown in black). In this case T2 or T(3 - 1) 3 8 Physically we have shown that 8 × 3 = 36 – 15 + 3 = T8 – T5 + T2 = T8 – T(8 – 3) + T(3 – 1) Which generalises to a × b = Ta – T(a – b) + T(b – 1) Rearranged for the algorithm a × b = Ta + T(b – 1) – T(a – b) Another approach to using triangle numbers is implied by this diagram which leads to a different algorithm. 3 8 a b a+b a+b a b a b A similar thing can be done using square numbers (or indeed any polygon numbers). The identity (a + b)2 = a2 + b2 + 2ab which is illustrated on the left can be rearranged to give ab = and the required algorithm can be produced from that. A table giving the values of square numbers Sn is available. Though interesting, and illuminating, to see how these work they were never more than mathematical curiosities, and (unlike the method of quarter squares) there appears to be no evidence that they were ever used in any practical way. One advantage this method does have over quarter squares is that, in this case the largest number in the tables is also the largest possible multiplier. © Frank Tapson 2004 [trolFG:5] Multiplication using Doubling and Halving 1. The Ancient Egyptian Method Consider the sum 268 × 43 First write out two columns of numbers side by side. The left-hand column starts with 1. The right-hand colum starts with the larger of the two numbers being multiplied (268). The columns are formed by doubling each of the previous numbers, stopping only when the figure in the left-hand column would become bigger than (or equal to) the other number being multiplied (43). The final result would be as shown on the right. Take care to keep the columns lined up, both vertically and horizontally. The next stage is to look at the left-hand column and find the numbers which are needed to add up to the value of the smaller multiplier (43). In this case the necessary set is 1 + 2 + 8 + 32 = 43 (Note that the bottom number should always be needed, and it is best working backwards from that, subtracting as you go.) Cross out all the numbers in that column not needed together with the numbers in the right-hand column which are on the same level. Finally, add up the numbers in the right-hand column which have not been crossed out. That is the answer. The completed sum is shown on the right. So, 268 × 43 = 11524 1 2 4 8 16 32 268 536 1072 2144 4288 8576 1 2 4 8 16 32 43 268 536 1072 2144 4288 8576 11524 Try these, using the Ancient Egyptian method. 26 × 314 41 × 61 71 × 213 55 × 97 32 × 104 2. The Russian Peasant Method Consider the sum 268 × 43 First write out two columns of numbers side by side. Each column starts with one of the two numbers to be multiplied. (43 and 268) Make one column by doubling each of the previous numbers. Make the other column by halving each of the previous numbers, ignoring any remainders, and stopping at 1. (It is best to make the halving column under the smaller of the two multipliers) 251 × 21 43 21 10 5 2 1 268 536 1072 2144 4288 8576 43 21 10 5 2 1 268 536 1072 2144 4288 8576 11524 The final result would be as shown on the right. Take care to keep the columns lined up, both vertically and horizontally. The next stage is to look at the halving column and find all the even numbers. In this case they are 10 and 2 Cross out the even numbers in that column together with the numbers in the right-hand column which are on the same level. Finally, add up the numbers in the right-hand column which have not been crossed out. That is the answer. The completed sum is shown on the right. So, 268 × 43 = 11524 Try these, using the Russian Peasant method. 24 × 316 © Frank Tapson 2004 [trolFG:6] 30 × 54 63 × 81 128 × 231 71 × 483 327 × 45 Multiplication using the Gelosia Method Consider the sum 268 × 43 (That is 3 digits × 2 digits) Sketch a grid like that on the right, and place the two numbers as shown. 2 6 × 8 4 3 Next, do the six single-digit multiplications formed by matching the separate numbers across the top with those on the right-hand edge. In this case, it means doing the six sums shown on the right and the answers to those multiplications are written in the appropriate boxes of the grid for each number-pair. 2×4 2×3 6×4 6×3 8×4 8×3 2 6 8 No answer can have more than two digits. (tens and units) Any tens (L.H. digit) are written above the diagonal line, The units (R.H. digit) are written below the diagonal line. (It may be zero) The completed grid should look like that on the right. 2 8 3 4 1 8 2 6 2 8 1 5 4 4 3 × 8 3 4 1 1 2 2 6 The final answer is produced by adding (the results of the multiplication only) along the diagonals, working from right to left, and carrying figures as necessary, and this is shown on the right. × 2 4 4 3 2 6 8 2 4 So, 268 × 43 = 11524 Try these, using the gelosia method. 386 × 24 758 × 34 76 × 89 Decimal points are dealt with very simply. Consider the sum 2.68 × 4.3 Work exactly as before with 268 × 43 and then put the two decimal points in those numbers on the vertical and horizontal lines respectively. Follow those two lines into the grid until they meet, and then, moving down the diagonal line from there, put the decimal point in the answer. All of this can be seen in the diagram on the right by following the arrows. So, 2.68 × 4.3 = 11.524 402 × 31 999 × 78 478 × 219 2 6 2 8 3 4 1 6 1 1 . 5 × 8 2 4 4 3 2 8 2 4 Try these, using the gelosia method. First, by using the grids already created in the previous work, write down the answers to these: 3.86 × 24 75.8 × 3.4 7.6 × 89 40.2 × 31 9.99 × 78 47.8 × 2.19 7.32 × 18 508 × 3.7 0.617 × 3.8 0.059 × 23 0.074 × 0.038 and then do these: 12.3 × 4.6 © Frank Tapson 2004 [trolFG:7] Multiplication using Quarter Squares The sheet headed Values of Quarter Squares Qn is needed The quarter square of a number, is the value of that number multiplied by itself and then divided by 4, ignoring any remainder (if there is one). Examples The quarter square of 2 is: 2 × 2 ÷ 4 = 4 ÷ 4 = 1 3 is: 3 × 3 ÷ 4 = 9 ÷ 4 = 2 rem 1 which becomes 2 5 is: 5 × 5 ÷ 4 = 25 ÷ 4 = 6 rem 1 which becomes 6 and so on. Quarter squares would be of little use for the purpose of simplifying multiplication if they had to be worked out each time they were needed and so a table is used to look up their values. Look at the sheet: Values of Quarter Squares and confirm that the quarter square of 413 is 42 642 (or 42,642 if preferred). Having such a table enables us to change a multiplication sum into a much simpler matter of addition and subtraction. Consider the sum 268 × 43 First add them: 268 + 43 = 311 and find the quarter square of that = 24 180 Then subtract them: 268 – 43 = 255 and find the quarter square of that = 12 656 Finally, subtract the quarter squares to get the final answer = 11 524 and 268 × 43 = 11 524 It could be set out something like this: × + – 268 43 311 225 Qn 24 180 12 656 – 11 524 Try these, using the quarter squares method. 245 × 32 © Frank Tapson 2004 [trolFG:8] 286 × 45 364 × 123 74 × 36 376 × 21 443 × 157 Multiplication using Triangle Numbers The sheet headed Values of Triangle Numbers Tn is needed T1 = 1 T2 = 3 T3 = 6 T4 = 10 T5 = 15 Triangle numbers are those that can be made in the way shown above where the first five are drawn. The actual value of any triangle number can be worked out using Tn = n × (n + 1) ÷ 2 Example The value of the triangle number for 8 is: 8 × (8 + 1) ÷ 2 = 8 × 9 ÷ 2 = 36 Triangle Numbers would be of little use for the purpose of simplifying multiplication if they had to be worked out each time they were needed and so a table is used to look up their values. Look at the sheet: Values of Triangle Numbers and confirm that the triangle number corresponding to 413 is 85 491 (or 85,491 if preferred). Having such a table enables us to change a multiplication sum into a much simpler matter of addition and subtraction. Consider the sum 268 × 43 Find the triangle number corresponding to the larger (268) Subtract 1 from the smaller (43 - 1 = 42) and find its triangle number Add those two triangle numbers Subtract the two multiplying numbers (268 - 43 = 225) and find the triangle number for that Subtract that from the previous result to get the final answer and 268 × 43 = 11 524 = 36 046 = 12 656 = 36 949 = 25 425 = 11 524 It could be set out something like this: Tn 268 36 046 43 – 1 = 42 903 + 36 949 – 225 25 425 – 11 524 Try these, using the triangle numbers method. 213 × 87 © Frank Tapson 2004 [trolFG:9] 367 × 42 179 × 53 485 × 132 593 × 341 259 × 34 Multiplication using Logarithms ~ 1 The sheet headed Values of Logarithms Ln is needed We will not concern ourselves here with what logarithms are, but only how to use them for multiplication. (They can also be used for division.) First of all, every number has a logarithm associated with it and that association is unique. In other words, given any number it has only one logarithm and, just as importantly, given any logarithm it can only represent one number. We will start with a very simple example of how we use logarithms. Consider the sum 2 × 4 To use the table of logarithms we need to see this as 2.00 × 4.00 From the table we can find that 2.00 has a logarithm of and that 4.00 has a logarithm of Then we ADD the two logarithms to get That is the answer to the sum but, it is a logarithm, so we need to find what number it represents. Using the table (in reverse) shows that 0.903 is the logarithm of 8.00 So 2.00 × 4.00 = 8.00 (Hardly a surprise, but good to see it works.) 0.301 0.602 0.903 Now consider the much harder sum 2.15 × 3.62 We find their logarithms are 0.332 and 0.559 and these add to 0.891 The logarithm 0.891 matches the number 7.78 So 2.15 × 3.62 = 7.78 It could be set out something like this: N 2.15 × 3.62 7.78 Ln 0.332 0.559 + 0.891 The full answer should have been 7.783 but it must be recognised that the very simplified table we are using is not capable of that sort of accuracy. We wish only to establish how logarithms are used and, for most practical purposes, this accuracy is adequate. Try doing these, using logarithms 2×3 © Frank Tapson 2004 [trolFG:10] 3×3 1.92 × 3.36 5.18 × 1.45 3.55 × 1.29 4.07 × 1.93 Multiplication using Logarithms ~ 2 Notice that the table of logarithms covers only numbers from 1.00 to 9.99 and that is true for all tables of logarithms. For greater accuracy it might be 1.0000 to 9.9999 but the principle is the same. So now we consider how to adapt all numbers to fit the tables and see how powerful this tool is in handling all multplications. For this we need to be familiar with a particular way of writing numbers which first sets them down as a value between 1 and 10 and then puts enough × 10's after them so they would be restored to their correct value. For example 43 can be written as 4.3 × 10 268 can be written as 2.68 × 10 × 10 There is a special notation used for this which writes the above numbers as 4.3e1 and 2.68e2 respectively where the number after the 'e' shows how many 10's are needed. Or it can be thought of as the amount that the decimal point must be moved to the right to restore the correct value. Now when we look up the logarithms of 4.3 and 2.68 we replace the 0 on the front with the e-number (if there is one). So that the logarithm of 43 (log 4.3 = 0.633 with e = 1) becomes 1.633 and the logarithm of 268 (log 2.68 = 0.428 with e = 2) becomes 2.428 Then we add the two logarithms to get 4.061 Remembering this stands for a logarithm of 0.061 with e = 4 We next find 0.061 in the logarithm tables and see that it corresponds to the number 1.15 With e = 4 we must multiply by 10, 4 times 1.15 × 10 × 10 × 10 × 10 = 11500 More accurately 43 × 268 = 11524 But we can write 43 × 268 = 11500 (to 3 significant figures) It could be set out something like this: N 43 × 268 1.15 Ln 1.633 2.428 + 4.061 Try doing these, using logarithms 37 × 26 © Frank Tapson 2004 [trolFG:11] 45 × 78 274 × 63 517 × 842 65.4 × 173 3610 × 904 © Frank Tapson 2004 [trolFG:12] Qn 0 1 2 4 6 9 12 16 20 25 30 36 42 49 56 64 72 81 90 100 110 121 132 144 156 169 182 196 210 225 240 256 272 289 306 324 342 361 380 400 420 441 462 484 506 529 552 576 600 625 n 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 96 97 98 99 100 91 92 93 94 95 86 87 88 89 90 81 82 83 84 85 76 77 78 79 80 71 72 73 74 75 66 67 68 69 70 61 62 63 64 65 56 57 58 59 60 51 52 53 54 55 n 2304 2352 2401 2450 2500 2070 2116 2162 2209 2256 1849 1892 1936 1980 2025 1640 1681 1722 1764 1806 1444 1482 1521 1560 1600 1260 1296 1332 1369 1406 1089 1122 1156 1190 1225 930 961 992 1024 1056 784 812 841 870 900 650 676 702 729 756 Qn 146 147 148 149 150 141 142 143 144 145 136 137 138 139 140 131 132 133 134 135 126 127 128 129 130 121 122 123 124 125 116 117 118 119 120 111 112 113 114 115 106 107 108 109 110 101 102 103 104 105 n 5329 5402 5476 5550 5625 4970 5041 5112 5184 5256 4624 4692 4761 4830 4900 4290 4356 4422 4489 4556 3969 4032 4096 4160 4225 3660 3721 3782 3844 3906 3364 3422 3481 3540 3600 3080 3136 3192 3249 3306 2809 2862 2916 2970 3025 2550 2601 2652 2704 2756 Qn 196 197 198 199 200 191 192 193 194 195 186 187 188 189 190 181 182 183 184 185 176 177 178 179 180 171 172 173 174 175 166 167 168 169 170 161 162 163 164 165 156 157 158 159 160 151 152 153 154 155 n 9604 9702 9801 9900 10 000 9120 9216 9312 9409 9506 8649 8742 8836 8930 9025 8190 8281 8372 8464 8556 7744 7832 7921 8010 8100 7310 7396 7482 7569 7656 6889 6972 7056 7140 7225 6480 6561 6642 6724 6806 6084 6162 6241 6320 6400 5700 5776 5852 5929 6006 Qn 246 247 248 249 250 241 242 243 244 245 236 237 238 239 240 231 232 233 234 235 226 227 228 229 230 221 222 223 224 225 216 217 218 219 220 211 212 213 214 215 206 207 208 209 210 201 202 203 204 205 n 100 201 302 404 506 210 321 432 544 656 15 15 15 15 15 14 14 14 14 15 13 14 14 14 14 13 13 13 13 13 129 252 376 500 625 520 641 762 884 006 924 042 161 280 400 340 456 572 689 806 12 769 12 882 12 996 13 110 13 225 12 12 12 12 12 11 664 11 772 11 881 11 990 12 100 11 130 11 236 11 342 11 449 11 556 10 609 10 712 10 816 10 920 11 025 10 10 10 10 10 Qn 296 297 298 299 300 291 292 293 294 295 286 287 288 289 290 281 282 283 284 285 276 277 278 279 280 271 272 273 274 275 266 267 268 269 270 261 262 263 264 265 256 257 258 259 260 251 252 253 254 255 n 21 22 22 22 22 21 21 21 21 21 20 20 20 20 21 19 19 20 20 20 19 19 19 19 19 18 18 18 18 18 17 17 17 18 18 17 17 17 17 17 16 16 16 16 16 15 15 16 16 16 904 052 201 350 500 170 316 462 609 756 449 592 736 880 025 740 881 022 164 306 044 182 321 460 600 360 496 632 769 906 689 822 956 090 225 030 161 292 424 556 384 512 641 770 900 750 876 002 129 256 Qn 346 347 348 349 350 341 342 343 344 345 336 337 338 339 340 331 332 333 334 335 326 327 328 329 330 321 322 323 324 325 316 317 318 319 320 311 312 313 314 315 306 307 308 309 310 301 302 303 304 305 n Values of Quarter Squares 29 30 30 30 30 29 29 29 29 29 28 28 28 28 28 27 27 27 27 28 26 26 26 27 27 25 25 26 26 26 24 25 25 25 25 24 24 24 24 24 23 23 23 23 24 22 22 22 23 23 929 102 276 450 625 070 241 412 584 756 224 392 561 730 900 390 556 722 889 056 569 732 896 060 225 760 921 082 244 406 964 122 281 440 600 180 336 492 649 806 409 562 716 870 025 650 801 952 104 256 Qn 396 397 398 399 400 391 392 393 394 395 386 387 388 389 390 381 382 383 384 385 376 377 378 379 380 371 372 373 374 375 366 367 368 369 370 361 362 363 364 365 356 357 358 359 360 351 352 353 354 355 n 39 39 39 39 40 38 38 38 38 39 37 37 37 37 38 36 36 36 36 37 35 35 35 35 36 34 34 34 34 35 33 33 33 34 34 32 32 32 33 33 31 31 32 32 32 30 30 31 31 31 204 402 601 800 000 220 416 612 809 006 249 442 636 830 025 290 481 672 864 056 344 532 721 910 100 410 596 782 969 156 489 672 856 040 225 580 761 942 124 306 684 862 041 220 400 800 976 152 329 506 Qn 446 447 448 449 450 441 442 443 444 445 436 437 438 439 440 431 432 433 434 435 426 427 428 429 430 421 422 423 424 425 416 417 418 419 420 411 412 413 414 415 406 407 408 409 410 401 402 403 404 405 n Q n for n = 1 to 600 49 49 50 50 50 48 48 49 49 49 47 47 47 48 48 46 46 46 47 47 45 45 45 46 46 44 44 44 44 45 43 43 43 43 44 42 42 42 42 43 41 41 41 41 42 40 40 40 40 41 729 952 176 400 625 620 841 062 284 506 524 742 961 180 400 440 656 872 089 306 369 582 796 010 225 310 521 732 944 156 264 472 681 890 100 230 436 642 849 056 209 412 616 820 025 200 401 602 804 006 Qn 496 497 498 499 500 491 492 493 494 495 486 487 488 489 490 481 482 483 484 485 476 477 478 479 480 471 472 473 474 475 466 467 468 469 470 461 462 463 464 465 456 457 458 459 460 451 452 453 454 455 n 61 61 62 62 62 60 60 60 61 61 59 59 59 59 60 57 58 58 58 58 56 56 57 57 57 55 55 55 56 56 54 54 54 54 55 53 53 53 53 54 51 52 52 52 52 50 51 51 51 51 504 752 001 250 500 270 516 762 009 256 049 292 536 780 025 840 081 322 564 806 644 882 121 360 600 460 696 932 169 406 289 522 756 990 225 130 361 592 824 056 984 212 441 670 900 850 076 302 529 756 Qn 546 547 548 549 550 541 542 543 544 545 536 537 538 539 540 531 532 533 534 535 526 527 528 529 530 521 522 523 524 525 516 517 518 519 520 511 512 513 514 515 506 507 508 509 510 501 502 503 504 505 n 74 74 75 75 75 73 73 73 73 74 71 72 72 72 72 70 70 71 71 71 69 69 69 69 70 67 68 68 68 68 66 66 67 67 67 65 65 65 66 66 64 64 64 64 65 62 63 63 63 63 529 802 076 350 625 170 441 712 984 256 824 092 361 630 900 490 756 022 289 556 169 432 696 960 225 860 121 382 644 906 564 822 081 340 600 280 536 792 049 306 009 262 516 770 025 750 001 252 504 756 Qn 596 597 598 599 600 591 592 593 594 595 586 587 588 589 590 581 582 583 584 585 576 577 578 579 580 571 572 573 574 575 566 567 568 569 570 561 562 563 564 565 556 557 558 559 560 551 552 553 554 555 n 88 89 89 89 90 87 87 87 88 88 85 86 86 86 87 84 84 84 85 85 82 83 83 83 84 81 81 82 82 82 80 80 80 80 81 78 78 79 79 79 77 77 77 78 78 75 76 76 76 77 804 102 401 700 000 320 616 912 209 506 849 142 436 730 025 390 681 972 264 556 944 232 521 810 100 510 796 082 369 656 089 372 656 940 225 680 961 242 524 806 284 562 841 120 400 900 176 452 729 006 Qn © Frank Tapson 2004 [trolFG:13] 136 153 171 190 210 231 253 276 300 325 351 378 406 435 465 496 528 561 595 630 666 703 741 780 820 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 861 42 903 43 946 44 990 45 1035 1081 1128 1176 1225 1275 91 92 93 94 95 66 78 91 105 120 11 12 13 14 15 46 47 48 49 50 86 87 88 89 90 21 28 36 45 55 6 7 8 9 10 96 97 98 99 100 81 82 83 84 85 76 77 78 79 80 71 72 73 74 75 66 67 68 69 70 61 62 63 64 65 56 57 58 59 60 51 52 53 54 55 1 3 6 10 15 1 2 3 4 5 n Tn n 4656 4753 4851 4950 5050 4186 4278 4371 4465 4560 3741 3828 3916 4005 4095 3321 3403 3486 3570 3655 2926 3003 3081 3160 3240 2556 2628 2701 2775 2850 2211 2278 2346 2415 2485 1891 1953 2016 2080 2145 1596 1653 1711 1770 1830 1326 1378 1431 1485 1540 Tn 146 147 148 149 150 141 142 143 144 145 136 137 138 139 140 131 132 133 134 135 126 127 128 129 130 121 122 123 124 125 116 117 118 119 120 111 112 113 114 115 106 107 108 109 110 101 102 103 104 105 n 10 731 10 878 11 026 11 175 11 325 10 011 10 153 10 296 10 440 10 585 9316 9453 9591 9730 9870 8646 8778 8911 9045 9180 8001 8128 8256 8385 8515 7381 7503 7626 7750 7875 6786 6903 7021 7140 7260 6216 6328 6441 6555 6670 5671 5778 5886 5995 6105 5151 5253 5356 5460 5565 Tn 196 197 198 199 200 191 192 193 194 195 186 187 188 189 190 181 182 183 184 185 176 177 178 179 180 171 172 173 174 175 166 167 168 169 170 161 162 163 164 165 156 157 158 159 160 151 152 153 154 155 n 706 878 051 225 400 861 028 196 365 535 041 203 366 530 695 246 403 561 720 880 391 578 766 955 145 471 653 836 020 205 19 19 19 19 20 306 503 701 900 100 18 336 18 528 18 721 18 915 19 110 17 17 17 17 18 16 16 16 17 17 15 576 15 753 15 931 16 110 16 290 14 14 15 15 15 13 14 14 14 14 13 13 13 13 13 12 12 12 12 12 11 476 11 628 11 781 11 935 12 090 Tn 246 247 248 249 250 241 242 243 244 245 236 237 238 239 240 231 232 233 234 235 226 227 228 229 230 221 222 223 224 225 216 217 218 219 220 211 212 213 214 215 206 207 208 209 210 201 202 203 204 205 n 30 30 30 31 31 29 29 29 29 30 27 28 28 28 28 26 27 27 27 27 25 25 26 26 26 24 24 24 25 25 23 23 23 24 24 22 22 22 23 23 21 21 21 21 22 381 628 876 125 375 161 403 646 890 135 966 203 441 680 920 796 028 261 495 730 651 878 106 335 565 531 753 976 200 425 436 653 871 090 310 366 578 791 005 220 321 528 736 945 155 20 301 20 503 20 706 20 910 21 115 Tn 296 297 298 299 300 291 292 293 294 295 286 287 288 289 290 281 282 283 284 285 276 277 278 279 280 271 272 273 274 275 266 267 268 269 270 261 262 263 264 265 256 257 258 259 260 251 252 253 254 255 n 626 878 131 385 640 191 453 716 980 245 43 44 44 44 45 42 42 43 43 43 41 41 41 41 42 39 39 40 40 40 38 38 38 39 39 36 37 37 37 37 956 253 551 850 150 486 778 071 365 660 041 328 616 905 195 621 903 186 470 755 226 503 781 060 340 856 128 401 675 950 35 511 35 778 36 046 36 315 36 585 34 34 34 34 35 32 896 33 153 33 411 33 670 33 930 31 31 32 32 32 Tn 48 48 49 49 49 50 50 50 51 51 51 52 52 52 52 53 53 53 54 54 54 946 55 278 55 611 55 945 56 280 56 56 57 57 57 58 311 58 653 58 996 59 340 59 685 60 60 60 61 61 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 031 378 726 075 425 616 953 291 630 970 301 628 956 285 615 681 003 326 650 975 086 403 721 040 360 516 828 141 455 770 971 278 586 895 205 46 47 47 47 48 306 307 308 309 310 451 753 056 360 665 45 45 46 46 46 Tn 396 397 398 399 400 391 392 393 394 395 386 387 388 389 390 381 382 383 384 385 376 377 378 379 380 371 372 373 374 375 366 367 368 369 370 361 362 363 364 365 356 357 358 359 360 351 352 353 354 355 n 78 79 79 79 80 76 77 77 77 78 74 75 75 75 76 72 73 73 73 74 70 71 71 72 72 69 69 69 70 70 67 67 67 68 68 65 65 66 66 66 63 63 64 64 64 61 62 62 62 63 606 003 401 800 200 636 028 421 815 210 691 078 466 855 245 771 153 536 920 305 876 253 631 010 390 006 378 751 125 500 161 528 896 265 635 341 703 066 430 795 546 903 261 620 980 776 128 481 835 190 Tn 446 447 448 449 450 441 442 443 444 445 436 437 438 439 440 431 432 433 434 435 426 427 428 429 430 421 422 423 424 425 416 417 418 419 420 411 412 413 414 415 406 407 408 409 410 401 402 403 404 405 n 99 100 100 101 101 97 97 98 98 99 95 95 96 96 97 93 93 93 94 94 90 91 91 92 92 88 89 89 90 90 86 87 87 87 88 84 85 85 85 86 82 83 83 83 84 80 81 81 81 82 Tn for n = 1 to 600 301 302 303 304 305 n Values of Triangle Numbers 681 128 576 025 475 461 903 346 790 235 266 703 141 580 020 096 528 961 395 830 951 378 806 235 665 831 253 676 100 525 736 153 571 990 410 666 078 491 905 320 621 028 436 845 255 601 003 406 810 215 Tn 926 378 831 285 740 106 106 107 107 108 491 953 416 880 345 104 196 104 653 105 111 105 570 106 030 101 102 102 103 103 Tn 496 497 498 499 500 491 492 493 494 495 526 003 481 960 440 123 123 124 124 125 120 121 121 122 122 256 753 251 750 250 786 278 771 265 760 341 828 316 805 295 115 921 116 403 116 886 117 370 117 855 113 114 114 114 115 111 156 111 628 112 101 112 575 113 050 486 118 487 118 488 119 489 119 490 120 481 482 483 484 485 476 477 478 479 480 471 472 473 474 475 466 108 811 467 109 278 468 109 746 469 110 215 470 110 685 461 462 463 464 465 456 457 458 459 460 451 452 453 454 455 n 546 547 548 549 550 541 542 543 544 545 536 537 538 539 540 531 532 533 534 535 526 527 528 529 530 521 522 523 524 525 516 517 518 519 520 511 512 513 514 515 506 507 508 509 510 501 502 503 504 505 n 601 128 656 185 715 981 503 026 550 075 386 903 421 940 460 816 328 841 355 870 271 778 286 795 305 751 253 756 260 765 916 453 991 530 070 149 149 150 150 151 331 878 426 975 525 146 611 147 153 147 696 148 240 148 785 143 144 144 145 146 141 246 141 778 142 311 142 845 143 380 138 139 139 140 140 135 136 137 137 138 133 133 134 134 135 130 131 131 132 132 128 128 129 129 130 125 126 126 127 127 Tn 596 597 598 599 600 591 592 593 594 595 586 587 588 589 590 581 582 583 584 585 576 577 578 579 580 571 572 573 574 575 566 567 568 569 570 561 562 563 564 565 556 557 558 559 560 551 552 553 554 555 n 177 178 179 179 180 174 175 176 176 177 171 172 173 173 174 169 169 170 170 171 166 166 167 167 168 163 163 164 165 165 160 161 161 162 162 157 158 158 159 159 154 155 155 156 157 152 152 153 153 154 906 503 101 700 300 936 528 121 715 310 991 578 166 755 345 071 653 236 820 405 176 753 331 910 490 306 878 451 025 600 461 028 596 165 735 641 203 766 330 895 846 403 961 520 080 076 628 181 735 290 Tn © Frank Tapson 2004 [trolFG:14] 51 52 53 54 55 1 4 9 16 25 36 49 64 81 100 121 144 169 196 225 256 289 324 361 400 441 484 529 576 625 676 729 784 841 900 961 1024 1089 1156 1225 1296 1369 1444 1521 1600 1681 1764 1849 1936 2025 2116 2209 2304 2401 2500 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 8281 8464 8649 8836 9025 7396 7569 7744 7921 8100 6561 6724 6889 7056 7225 5776 5929 6084 6241 6400 5041 5184 5329 5476 5625 4356 4489 4624 4761 4900 3721 3844 3969 4096 4225 3136 3249 3364 3481 3600 2601 2704 2809 2916 3025 Sn 96 9216 97 9409 98 9604 99 9801 100 10 000 91 92 93 94 95 86 87 88 89 90 81 82 83 84 85 76 77 78 79 80 71 72 73 74 75 66 67 68 69 70 61 62 63 64 65 56 57 58 59 60 n n Sn 146 147 148 149 150 141 142 143 144 145 136 137 138 139 140 131 132 133 134 135 126 127 128 129 130 121 122 123 124 125 116 117 118 119 120 111 112 113 114 115 106 107 108 109 110 101 102 103 104 105 n 21 21 21 22 22 19 20 20 20 21 18 18 19 19 19 17 17 17 17 18 15 16 16 16 16 14 14 15 15 15 13 13 13 14 14 12 12 12 12 13 316 609 904 201 500 881 164 449 736 025 496 769 044 321 600 161 424 689 956 225 876 129 384 641 900 641 884 129 376 625 456 689 924 161 400 321 544 769 996 225 11 236 11 449 11 664 11 881 12 100 10 201 10 404 10 609 10 816 11 025 Sn 196 197 198 199 200 191 192 193 194 195 186 187 188 189 190 181 182 183 184 185 176 177 178 179 180 171 172 173 174 175 166 167 168 169 170 161 162 163 164 165 156 157 158 159 160 151 152 153 154 155 n 38 38 39 39 40 36 36 37 37 38 34 34 35 35 36 32 33 33 33 34 30 31 31 32 32 29 29 29 30 30 27 27 28 28 28 25 26 26 26 27 24 24 24 25 25 22 23 23 23 24 416 809 204 601 000 481 864 249 636 025 596 969 344 721 100 761 124 489 856 225 976 329 684 041 400 241 584 929 276 625 556 889 224 561 900 921 244 569 896 225 336 649 964 281 600 801 104 409 716 025 Sn 246 247 248 249 250 241 242 243 244 245 236 237 238 239 240 231 232 233 234 235 226 227 228 229 230 221 222 223 224 225 216 217 218 219 220 211 212 213 214 215 206 207 208 209 210 201 202 203 204 205 n 60 61 61 62 62 58 58 59 59 60 55 56 56 57 57 53 53 54 54 55 51 51 51 52 52 48 49 49 50 50 46 47 47 47 48 44 44 45 45 46 42 42 43 43 44 40 40 41 41 42 516 009 504 001 500 081 564 049 536 025 696 169 644 121 600 361 824 289 756 225 076 529 984 441 900 841 284 729 176 625 656 089 524 961 400 521 944 369 796 225 436 849 264 681 100 401 804 209 616 025 Sn 296 297 298 299 300 291 292 293 294 295 286 287 288 289 290 281 282 283 284 285 276 277 278 279 280 271 272 273 274 275 266 267 268 269 270 261 262 263 264 265 256 257 258 259 260 251 252 253 254 255 n 87 88 88 89 90 84 85 85 86 87 81 82 82 83 84 78 79 80 80 81 76 76 77 77 78 73 73 74 75 75 70 71 71 72 72 68 68 69 69 70 65 66 66 67 67 63 63 64 64 65 616 209 804 401 000 681 264 849 436 025 796 369 944 521 100 961 524 089 656 225 176 729 284 841 400 441 984 529 076 625 756 289 824 361 900 121 644 169 696 225 536 049 564 081 600 001 504 009 516 025 Sn 346 347 348 349 350 341 342 343 344 345 336 337 338 339 340 331 332 333 334 335 326 327 328 329 330 321 322 323 324 325 316 317 318 319 320 311 312 313 314 315 306 307 308 309 310 301 302 303 304 305 n 96 97 97 98 99 93 94 94 95 96 90 91 91 92 93 276 929 584 241 900 041 684 329 976 625 856 489 124 761 400 721 344 969 596 225 636 249 864 481 100 601 204 809 416 025 Sn 119 120 121 121 122 116 116 117 118 119 112 113 114 114 115 716 409 104 801 500 281 964 649 336 025 896 569 244 921 600 396 397 398 399 400 391 392 393 394 395 386 387 388 389 390 381 382 383 384 385 376 377 378 379 380 371 372 373 374 375 366 367 368 369 370 361 362 363 364 365 356 357 358 359 360 351 352 353 354 355 n 156 157 158 159 160 152 153 154 155 156 148 149 150 151 152 145 145 146 147 148 141 142 142 143 144 137 138 139 139 140 133 134 135 136 136 130 131 131 132 133 126 127 128 128 129 123 123 124 125 126 816 609 404 201 000 881 664 449 236 025 996 769 544 321 100 161 924 689 456 225 376 129 884 641 400 641 384 129 876 625 956 689 424 161 900 321 044 769 496 225 736 449 164 881 600 201 904 609 316 025 Sn 446 447 448 449 450 441 442 443 444 445 436 437 438 439 440 431 432 433 434 435 426 427 428 429 430 421 422 423 424 425 416 417 418 419 420 411 412 413 414 415 406 407 408 409 410 401 402 403 404 405 n Sn for n = 1 to 600 109 561 110 224 110 889 111 556 112 225 106 106 107 108 108 103 103 104 104 105 99 100 101 101 102 Values of Square Numbers 198 199 200 201 202 194 195 196 197 198 190 190 191 192 193 185 186 187 188 189 181 182 183 184 184 177 178 178 179 180 173 173 174 175 176 168 169 170 171 172 164 165 166 167 168 160 161 162 163 164 916 809 704 601 500 481 364 249 136 025 096 969 844 721 600 761 624 489 356 225 476 329 184 041 900 241 084 929 776 625 056 889 724 561 400 921 744 569 396 225 836 649 464 281 100 801 604 409 216 025 Sn 496 497 498 499 500 491 492 493 494 495 486 487 488 489 490 481 482 483 484 485 476 477 478 479 480 471 472 473 474 475 466 467 468 469 470 461 462 463 464 465 456 457 458 459 460 451 452 453 454 455 n 246 247 248 249 250 241 242 243 244 245 236 237 238 239 240 231 232 233 234 235 226 227 228 229 230 221 222 223 224 225 217 218 219 219 220 212 213 214 215 216 016 009 004 001 000 081 064 049 036 025 196 169 144 121 100 361 324 289 256 225 576 529 484 441 400 841 784 729 676 625 156 089 024 961 900 521 444 369 296 225 207 936 208 849 209 764 210 681 211 600 203 401 204 304 205 209 206 116 207 025 Sn 546 547 548 549 550 541 542 543 544 545 536 537 538 539 540 531 532 533 534 535 526 527 528 529 530 521 522 523 524 525 516 517 518 519 520 511 512 513 514 515 506 507 508 509 510 501 502 503 504 505 n 681 764 849 936 025 296 369 444 521 600 961 024 089 156 225 676 729 784 841 900 441 484 529 576 625 256 289 324 361 400 121 144 169 196 225 036 049 064 081 100 001 004 009 016 025 298 116 299 209 300 304 301 401 302 500 292 293 294 295 297 287 288 289 290 291 281 283 284 285 286 276 277 278 279 280 271 272 273 274 275 266 267 268 269 270 261 262 263 264 265 256 257 258 259 260 251 252 253 254 255 Sn 596 597 598 599 600 591 592 593 594 595 586 587 588 589 590 581 582 583 584 585 576 577 578 579 580 571 572 573 574 575 566 567 568 569 570 561 562 563 564 565 556 557 558 559 560 551 552 553 554 555 n 355 356 357 358 360 349 350 351 352 354 343 344 345 346 348 337 338 339 341 342 331 332 334 335 336 326 327 328 329 330 320 321 322 323 324 314 315 316 318 319 309 310 311 312 313 303 304 305 306 308 216 409 604 801 000 281 464 649 836 025 396 569 744 921 100 561 724 889 056 225 776 929 084 241 400 041 184 329 476 625 356 489 624 761 900 721 844 969 096 225 136 249 364 481 600 601 704 809 916 025 Sn © Frank Tapson 2004 [trolFG:15] 0.176 0.204 0.230 0.255 0.279 0.301 0.322 0.342 0.362 0.380 0.398 0.415 0.431 0.447 0.462 0.477 0.491 0.505 0.519 0.531 0.544 0.556 0.568 0.580 0.591 0.602 0.613 0.623 0.633 0.643 0.653 0.663 0.672 0.681 0.690 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 0.654 0.664 0.673 0.682 0.691 0.603 0.614 0.624 0.634 0.644 0.545 0.558 0.569 0.581 0.592 0.479 0.493 0.507 0.520 0.533 0.400 0.417 0.433 0.449 0.464 0.303 0.324 0.344 0.364 0.382 0.179 0.207 0.233 0.258 0.281 1 0.004 0.045 0.083 0.117 0.149 0.655 0.665 0.674 0.683 0.692 0.604 0.615 0.625 0.635 0.645 0.547 0.559 0.571 0.582 0.593 0.480 0.494 0.508 0.521 0.534 0.401 0.418 0.435 0.450 0.465 0.305 0.326 0.346 0.365 0.384 0.182 0.210 0.236 0.260 0.283 2 0.009 0.049 0.086 0.121 0.152 0.656 0.666 0.675 0.684 0.693 0.605 0.616 0.626 0.636 0.646 0.548 0.560 0.572 0.583 0.594 0.481 0.496 0.509 0.522 0.535 0.403 0.420 0.436 0.452 0.467 0.308 0.328 0.348 0.367 0.386 0.185 0.212 0.238 0.262 0.286 3 0.013 0.053 0.090 0.124 0.155 0.657 0.667 0.676 0.685 0.694 0.606 0.617 0.627 0.637 0.647 0.549 0.561 0.573 0.584 0.596 0.483 0.497 0.510 0.524 0.537 0.405 0.422 0.438 0.453 0.468 0.310 0.330 0.350 0.369 0.387 0.188 0.215 0.241 0.265 0.288 4 0.017 0.057 0.093 0.127 0.158 0.658 0.667 0.677 0.686 0.695 0.607 0.618 0.628 0.638 0.648 0.550 0.562 0.574 0.585 0.597 0.484 0.498 0.512 0.525 0.538 0.407 0.423 0.439 0.455 0.470 0.312 0.332 0.352 0.371 0.389 0.190 0.217 0.243 0.267 0.290 5 0.021 0.061 0.097 0.130 0.161 0.659 0.668 0.678 0.687 0.695 0.609 0.619 0.629 0.639 0.649 0.551 0.563 0.575 0.587 0.598 0.486 0.500 0.513 0.526 0.539 0.408 0.425 0.441 0.456 0.471 0.314 0.334 0.354 0.373 0.391 0.193 0.220 0.245 0.270 0.292 6 0.025 0.064 0.100 0.134 0.164 0.660 0.669 0.679 0.688 0.696 0.610 0.620 0.630 0.640 0.650 0.553 0.565 0.576 0.588 0.599 0.487 0.501 0.515 0.528 0.540 0.410 0.427 0.442 0.458 0.473 0.316 0.336 0.356 0.375 0.393 0.196 0.223 0.248 0.272 0.294 7 0.029 0.068 0.104 0.137 0.167 0.661 0.670 0.679 0.688 0.697 0.611 0.621 0.631 0.641 0.651 0.554 0.566 0.577 0.589 0.600 0.489 0.502 0.516 0.529 0.542 0.412 0.428 0.444 0.459 0.474 0.318 0.338 0.358 0.377 0.394 0.199 0.225 0.250 0.274 0.297 8 0.033 0.072 0.107 0.140 0.170 To find the value of the logarithm of n Match the first two digits of n (containing the decimal point) with those in the left-hand column of the table. Go along that line of the table to the three figure decimal number which lies directly under the value at the head of the table matching the third digit of n. That will be the logarithm of n. 0 0.000 0.041 0.079 0.114 0.146 1.0 1.1 1.2 1.3 1.4 0.662 0.671 0.680 0.689 0.698 0.612 0.622 0.632 0.642 0.652 0.555 0.567 0.579 0.590 0.601 0.490 0.504 0.517 0.530 0.543 0.413 0.430 0.446 0.461 0.476 0.320 0.340 0.360 0.378 0.396 0.201 0.228 0.253 0.276 0.299 9 0.037 0.076 0.111 0.143 0.173 Values of Logarithms 0 0.929 0.935 0.940 0.944 0.949 0.954 0.959 0.964 0.968 0.973 0.978 0.982 0.987 0.991 0.996 9.0 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 9.9 0.903 0.908 0.914 0.919 0.924 0.875 0.881 0.886 0.892 0.898 0.845 0.851 0.857 0.863 0.869 0.813 0.820 0.826 0.833 0.839 0.778 0.785 0.792 0.799 0.806 0.740 0.748 0.756 0.763 0.771 0.699 0.708 0.716 0.724 0.732 8.5 8.6 8.7 8.8 8.9 8.0 8.1 8.2 8.3 8.4 7.5 7.6 7.7 7.8 7.9 7.0 7.1 7.2 7.3 7.4 6.5 6.6 6.7 6.8 6.9 6.0 6.1 6.2 6.3 6.4 5.5 5.6 5.7 5.8 5.9 5.0 5.1 5.2 5.3 5.4 Ln for n = 1.0 0.978 0.983 0.987 0.992 0.996 0.955 0.960 0.964 0.969 0.974 0.930 0.935 0.940 0.945 0.950 0.904 0.909 0.914 0.920 0.925 0.876 0.881 0.887 0.893 0.898 0.846 0.852 0.858 0.864 0.870 0.814 0.820 0.827 0.833 0.839 0.779 0.786 0.793 0.800 0.807 0.741 0.749 0.757 0.764 0.772 0.700 0.708 0.717 0.725 0.733 1 0.979 0.983 0.988 0.992 0.997 0.955 0.960 0.965 0.969 0.974 0.930 0.936 0.941 0.945 0.950 0.904 0.910 0.915 0.920 0.925 0.876 0.882 0.888 0.893 0.899 0.846 0.852 0.859 0.865 0.870 0.814 0.821 0.827 0.834 0.840 0.780 0.787 0.794 0.801 0.808 0.742 0.750 0.757 0.765 0.772 0.700 0.709 0.718 0.726 0.734 2 to 9.99 3 0.979 0.984 0.988 0.993 0.997 0.956 0.960 0.965 0.970 0.975 0.931 0.936 0.941 0.946 0.951 0.905 0.910 0.915 0.921 0.926 0.877 0.883 0.888 0.894 0.899 0.847 0.853 0.859 0.865 0.871 0.815 0.822 0.828 0.834 0.841 0.780 0.787 0.794 0.801 0.808 0.743 0.751 0.758 0.766 0.773 0.702 0.711 0.719 0.727 0.735 4 0.980 0.984 0.989 0.993 0.997 0.956 0.961 0.966 0.970 0.975 0.931 0.937 0.942 0.946 0.951 0.905 0.911 0.916 0.921 0.926 0.877 0.883 0.889 0.894 0.900 0.848 0.854 0.860 0.866 0.872 0.816 0.822 0.829 0.835 0.841 0.781 0.788 0.795 0.802 0.809 0.744 0.751 0.759 0.766 0.774 0.702 0.710 0.719 0.728 0.736 5 0.980 0.985 0.989 0.993 0.998 0.957 0.961 0.966 0.971 0.975 0.932 0.937 0.942 0.947 0.952 0.906 0.911 0.916 0.922 0.927 0.878 0.884 0.889 0.895 0.900 0.848 0.854 0.860 0.866 0.872 0.816 0.823 0.829 0.836 0.842 0.782 0.789 0.796 0.803 0.810 0.744 0.752 0.760 0.767 0.775 0.703 0.712 0.720 0.728 0.736 6 0.980 0.985 0.989 0.994 0.998 0.957 0.962 0.967 0.971 0.976 0.932 0.938 0.943 0.947 0.952 0.906 0.912 0.917 0.922 0.927 0.879 0.884 0.890 0.895 0.901 0.849 0.855 0.861 0.867 0.873 0.817 0.823 0.830 0.836 0.843 0.782 0.790 0.797 0.803 0.810 0.745 0.753 0.760 0.768 0.775 0.704 0.713 0.721 0.729 0.737 7 0.981 0.985 0.990 0.994 0.999 0.958 0.962 0.967 0.972 0.976 0.933 0.938 0.943 0.948 0.953 0.907 0.912 0.918 0.923 0.928 0.879 0.885 0.890 0.896 0.901 0.849 0.856 0.861 0.867 0.873 0.818 0.824 0.831 0.837 0.843 0.783 0.790 0.797 0.804 0.811 0.746 0.754 0.761 0.769 0.776 0.705 0.713 0.722 0.730 0.738 8 0.981 0.986 0.990 0.995 0.999 0.958 0.963 0.968 0.972 0.977 0.933 0.939 0.943 0.948 0.953 0.907 0.913 0.918 0.923 0.928 0.880 0.885 0.891 0.897 0.902 0.850 0.856 0.862 0.868 0.874 0.818 0.825 0.831 0.838 0.844 0.784 0.791 0.798 0.805 0.812 0.747 0.754 0.762 0.769 0.777 0.706 0.714 0.723 0.731 0.739 9 0.982 0.986 0.991 0.995 1.000 0.959 0.963 0.968 0.973 0.977 0.934 0.939 0.944 0.949 0.954 0.908 0.913 0.919 0.924 0.929 0.880 0.886 0.892 0.897 0.903 0.851 0.857 0.863 0.869 0.874 0.819 0.825 0.832 0.838 0.844 0.785 0.792 0.799 0.806 0.812 0.747 0.755 0.763 0.770 0.777 0.707 0.715 0.723 0.732 0.740 × 1 2 3 4 5 6 7 8 9 × 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 2 4 6 8 10 12 14 16 18 2 4 6 8 10 12 14 16 18 3 6 9 12 15 18 21 24 27 3 6 9 12 15 18 21 24 27 4 8 12 16 20 24 28 32 36 4 8 12 16 20 24 28 32 36 9 18 27 36 45 54 63 72 81 1 2 3 4 5 6 7 8 9 × 1 2 3 4 5 6 7 8 9 × 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 2 4 6 8 10 12 14 16 18 2 4 6 8 10 12 14 16 18 3 6 9 12 15 18 21 24 27 3 6 9 12 15 18 21 24 27 4 8 12 16 20 24 28 32 36 4 8 12 16 20 24 28 32 36 9 18 27 36 45 54 63 72 81 1 2 3 4 5 6 7 8 9 × 1 2 3 4 5 6 7 8 9 × 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 2 4 6 8 10 12 14 16 18 2 4 6 8 10 12 14 16 18 3 6 9 12 15 18 21 24 27 3 6 9 12 15 18 21 24 27 4 8 12 16 20 24 28 32 36 4 8 12 16 20 24 28 32 36 9 18 27 36 45 54 63 72 81 1 2 3 4 5 6 7 8 9 × 1 2 3 4 5 6 7 8 9 × 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 2 4 6 8 10 12 14 16 18 2 4 6 8 10 12 14 16 18 3 6 9 12 15 18 21 24 27 3 6 9 12 15 18 21 24 27 4 8 12 16 20 24 28 32 36 1 2 3 4 5 6 7 8 9 4 8 12 16 20 24 28 32 36 5 10 15 20 25 30 35 40 45 6 12 18 24 30 36 42 48 54 7 14 21 28 35 42 49 56 63 8 16 24 32 40 48 56 64 72 5 10 15 20 25 30 35 40 45 6 12 18 24 30 36 42 48 54 7 14 21 28 35 42 49 56 63 8 16 24 32 40 48 56 64 72 5 10 15 20 25 30 35 40 45 6 12 18 24 30 36 42 48 54 7 14 21 28 35 42 49 56 63 8 16 24 32 40 48 56 64 72 5 10 15 20 25 30 35 40 45 6 12 18 24 30 36 42 48 54 7 14 21 28 35 42 49 56 63 8 16 24 32 40 48 56 64 72 9 18 27 36 45 54 63 72 81 © Frank Tapson 2004 [trolFG:16] 5 10 15 20 25 30 35 40 45 6 12 18 24 30 36 42 48 54 7 14 21 28 35 42 49 56 63 8 16 24 32 40 48 56 64 72 9 18 27 36 45 54 63 72 81 5 10 15 20 25 30 35 40 45 6 12 18 24 30 36 42 48 54 7 14 21 28 35 42 49 56 63 8 16 24 32 40 48 56 64 72 9 18 27 36 45 54 63 72 81 5 10 15 20 25 30 35 40 45 6 12 18 24 30 36 42 48 54 7 14 21 28 35 42 49 56 63 8 16 24 32 40 48 56 64 72 9 18 27 36 45 54 63 72 81 5 10 15 20 25 30 35 40 45 6 12 18 24 30 36 42 48 54 7 14 21 28 35 42 49 56 63 8 16 24 32 40 48 56 64 72 9 18 27 36 45 54 63 72 81 × × × × × × × 3 4 5 6 7 8 9 = = = = = = = 216 288 360 432 504 576 648 213 284 355 426 497 568 639 × × × × × × × 3 4 5 6 7 8 9 = = = = = = = 219 292 365 438 511 584 657 64 96 128 160 192 224 256 288 32 × 2 = 66 99 132 165 198 231 264 297 33 × 2 = = = = = = = = 3 4 5 6 7 8 9 3 4 5 6 7 8 9 = = = = = = = = 158 237 316 395 474 553 632 711 154 231 308 385 462 539 616 693 × × × × × × × = = = = = = = 2 3 4 5 6 7 8 9 = = = = = = = = 33 33 33 33 33 33 33 = = = = = = = 3 4 5 6 7 8 9 77 77 77 77 77 77 77 2 3 4 5 6 7 8 9 × × × × × × × 32 32 32 32 32 32 32 225 300 375 450 525 600 675 = = = = = = = 75 75 75 75 75 75 75 222 296 370 444 518 592 666 79 × × × × × × × × = = = = = = = 152 228 304 380 456 532 608 684 79 79 79 79 79 79 79 3 4 5 6 7 8 9 = = = = = = = = 156 234 312 390 468 546 624 702 162 243 324 405 486 567 648 729 × × × × × × × 2 3 4 5 6 7 8 9 = = = = = = = = = = = = = = = = 31 31 31 31 31 31 31 76 76 76 76 76 76 76 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 3 4 5 6 7 8 9 62 93 124 155 186 217 248 279 31 × 2 = 78 × × × × × × × × 81 × × × × × × × × × × × × × × × 60 90 120 150 180 210 240 270 46 69 92 115 138 161 184 207 78 78 78 78 78 78 78 81 81 81 81 81 81 81 = = = = = = = = = = = = = = = = = = = = = = 50 75 100 125 150 175 200 225 160 240 320 400 480 560 640 720 3 4 5 6 7 8 9 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 = = = = = = = = = = = = = = = = × × × × × × × × × × × × × × 58 87 116 145 174 203 232 261 29 29 29 29 29 29 29 29 × 2 = 23 23 23 23 23 23 23 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 30 30 30 30 30 30 30 = = = = = = = 30 × 2 = 3 4 5 6 7 8 9 25 × × × × × × × × 80 × × × × × × × × 75 × 2 = 150 73 73 73 73 73 73 73 × × × × × × × 56 84 112 140 168 196 224 252 28 28 28 28 28 28 28 28 × 2 = 44 66 88 110 132 154 176 198 25 25 25 25 25 25 25 80 80 80 80 80 80 80 × × × × × × × = = = = = = = = = = = = = = = 48 72 96 120 144 168 192 216 54 81 108 135 162 189 216 243 74 74 74 74 74 74 74 3 4 5 6 7 8 9 73 × 2 = 146 × × × × × × × 2 3 4 5 6 7 8 9 = = = = = = = = = = = = = = = = 77 × × × × × × × × 22 22 22 22 22 22 22 2 3 4 5 6 7 8 9 27 × × × × × × × × 76 × × × × × × × × 24 × × × × × × × × 52 78 104 130 156 182 208 234 23 × × × × × × × × 24 24 24 24 24 24 24 = = = = = = = = 22 × × × × × × × × 26 × × × × × × × × 74 × 2 = 148 72 72 72 72 72 72 72 72 × 2 = 144 71 71 71 71 71 71 71 98 147 196 245 294 343 392 441 49 × 2 = × × × × × × × 3 4 5 6 7 8 9 = = = = = = = × × × × × × × 3 4 5 6 7 8 9 = = = = = = = 150 200 250 300 350 400 450 × × × × × × × 3 4 5 6 7 8 9 = = = = = = = 153 204 255 306 357 408 459 51 51 51 51 51 51 51 49 49 49 49 49 49 49 = = = = = = = 51 × 2 = 102 = = = = = = = 3 4 5 6 7 8 9 50 50 50 50 50 50 50 3 4 5 6 7 8 9 × × × × × × × 94 141 188 235 282 329 376 423 47 47 47 47 47 47 47 47 × 2 = 50 × 2 = 100 × × × × × × × = = = = = = = 96 144 192 240 288 336 384 432 48 48 48 48 48 48 48 3 4 5 6 7 8 9 48 × 2 = × × × × × × × 92 138 184 230 276 322 368 414 46 46 46 46 46 46 46 46 × 2 = × × × × × × × 3 4 5 6 7 8 9 = = = = = = = 156 208 260 312 364 416 468 × × × × × × × 3 4 5 6 7 8 9 = = = = = = = 162 216 270 324 378 432 486 56 56 56 56 56 56 56 × × × × × × × 3 4 5 6 7 8 9 × × × × × × × 3 4 5 6 7 8 9 = = = = = = = 159 212 265 318 371 424 477 × × × × × × × 3 4 5 6 7 8 9 = = = = = = = 165 220 275 330 385 440 495 57 57 57 57 57 57 57 168 224 280 336 392 448 504 × × × × × × × 171 228 285 342 399 456 513 = = = = = = = 3 4 5 6 7 8 9 57 × 2 = 114 55 55 55 55 55 55 55 55 × 2 = 110 53 53 53 53 53 53 53 53 × 2 = 106 = = = = = = = 56 × 2 = 112 54 54 54 54 54 54 54 54 × 2 = 108 52 52 52 52 52 52 52 52 × 2 = 104 190 285 380 475 570 665 760 855 2 3 4 5 6 7 8 9 71 × 2 = 142 = = = = = = = = 27 27 27 27 27 27 27 210 280 350 420 490 560 630 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 = = = = = = = 95 × × × × × × × × 95 95 95 95 95 95 95 26 26 26 26 26 26 26 3 4 5 6 7 8 9 188 282 376 470 564 658 752 846 194 291 388 485 582 679 776 873 198 297 396 495 594 693 792 891 × × × × × × × = = = = = = = = = = = = = = = = = = = = = = = = 70 70 70 70 70 70 70 2 3 4 5 6 7 8 9 97 × × × × × × × × 97 97 97 97 97 97 97 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 192 288 384 480 576 672 768 864 99 99 99 99 99 99 99 99 × × × × × × × × 196 294 392 490 588 686 784 882 70 × 2 = 140 94 × × × × × × × × 94 94 94 94 94 94 94 96 × × × × × × × × 96 96 96 96 96 96 96 = = = = = = = = = = = = = = = = × 1 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 98 × × × × × × × × 98 98 98 98 98 98 98 © Frank Tapson 2004 [trolFG:17] Multiplication Tables 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 2 4 6 8 10 12 14 16 18 3 6 9 12 15 18 21 24 27 4 8 12 16 20 24 28 32 36 5 10 15 20 25 30 35 40 45 6 12 18 24 30 36 42 48 54 7 14 21 28 35 42 49 56 63 8 16 24 32 40 48 56 64 72 9 18 27 36 45 54 63 72 81 = = = = = = = 246 328 410 492 574 656 738 × × × × × × × 3 4 5 6 7 8 9 = = = = = = = 252 336 420 504 588 672 756 = = = = = = = 249 332 415 498 581 664 747 × × × × × × × 3 4 5 6 7 8 9 = = = = = = = 255 340 425 510 595 680 765 40 60 80 100 120 140 160 180 20 × 2 = 42 63 84 105 126 147 168 189 21 × 2 = 270 360 450 540 630 720 810 3 4 5 6 7 8 9 = = = = = = = 273 364 455 546 637 728 819 279 372 465 558 651 744 837 = = = = = = = 3 4 5 6 7 8 9 258 344 430 516 602 688 774 67 × × × × × × × × 65 65 65 65 65 65 65 = = = = = = = 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 3 4 5 6 7 8 9 = = = = = = = = = = = = = = = = 134 201 268 335 402 469 536 603 130 195 260 325 390 455 520 585 × × × × × × × 93 93 93 93 93 93 93 276 368 460 552 644 736 828 = = = = = = = 3 4 5 6 7 8 9 92 92 92 92 92 92 92 45 60 75 90 105 120 135 15 15 15 15 15 15 15 42 56 70 84 98 112 126 = = = = = = = 3 4 5 6 7 8 9 × × × × × × × 20 20 20 20 20 20 20 261 348 435 522 609 696 783 = = = = = = = 3 4 5 6 7 8 9 87 87 87 87 87 87 87 128 192 256 320 384 448 512 576 67 67 67 67 67 67 67 93 × 2 = 186 × × × × × × × = = = = = = = = 132 198 264 330 396 462 528 594 × × × × × × × 91 91 91 91 91 91 91 91 × 2 = 182 267 356 445 534 623 712 801 2 3 4 5 6 7 8 9 = = = = = = = = 138 207 276 345 414 483 552 621 92 × 2 = 184 = = = = = = = = = = = = = = 64 64 64 64 64 64 64 2 3 4 5 6 7 8 9 = = = = = = = = = = = = = = = 3 4 5 6 7 8 9 3 4 5 6 7 8 9 66 × × × × × × × × 2 3 4 5 6 7 8 9 3 4 5 6 7 8 9 × × × × × × × × × × × × × × 70 105 140 175 210 245 280 315 66 66 66 66 66 66 66 69 × × × × × × × × × × × × × × × 90 90 90 90 90 90 90 90 × 2 = 180 89 89 89 89 89 89 89 89 × 2 = 178 = = = = = = = = 74 111 148 185 222 259 296 333 69 69 69 69 69 69 69 15 × 2 = 30 39 52 65 78 91 104 117 264 352 440 528 616 704 792 2 3 4 5 6 7 8 9 = = = = = = = = 136 204 272 340 408 476 544 612 14 14 14 14 14 14 14 = = = = = = = = = = = = = = 35 35 35 35 35 35 35 2 3 4 5 6 7 8 9 = = = = = = = = 14 × 2 = 28 3 4 5 6 7 8 9 3 4 5 6 7 8 9 37 × × × × × × × × 2 3 4 5 6 7 8 9 = = = = = = = × × × × × × × × × × × × × × 68 102 136 170 204 238 272 306 37 37 37 37 37 37 37 68 × × × × × × × × 3 4 5 6 7 8 9 13 13 13 13 13 13 13 13 × 2 = 26 88 88 88 88 88 88 88 88 × 2 = 176 = = = = = = = = 72 108 144 180 216 252 288 324 68 68 68 68 68 68 68 × × × × × × × = 36 = 48 = 60 = 72 = 84 = 96 = 108 33 44 55 66 77 88 99 2 3 4 5 6 7 8 9 = = = = = = = = 78 117 156 195 234 273 312 351 21 21 21 21 21 21 21 3 4 5 6 7 8 9 = = = = = = = 34 34 34 34 34 34 34 2 3 4 5 6 7 8 9 = = = = = = = = = = = = = = = × × × × × × × 3 4 5 6 7 8 9 36 × × × × × × × × 39 × × × × × × × × 3 4 5 6 7 8 9 12 12 12 12 12 12 12 12 × 2 = 24 × × × × × × × 82 123 164 205 246 287 328 369 36 36 36 36 36 36 36 76 114 152 190 228 266 304 342 = = = = = = = 11 11 11 11 11 11 11 11 × 2 = 22 = = = = = = = = 86 129 172 215 258 301 344 387 = = = = = = = = 3 4 5 6 7 8 9 30 40 50 60 70 80 90 2 3 4 5 6 7 8 9 = = = = = = = = 38 × × × × × × × × × × × × × × × = = = = = = = 41 41 41 41 41 41 41 2 3 4 5 6 7 8 9 90 135 180 225 270 315 360 405 19 19 19 19 19 19 19 3 4 5 6 7 8 9 43 × × × × × × × × = = = = = = = = × × × × × × × 38 57 76 95 114 133 152 171 19 × 2 = × × × × × × × 80 120 160 200 240 280 320 360 43 43 43 43 43 43 43 2 3 4 5 6 7 8 9 = = = = = = = 10 10 10 10 10 10 10 10 × 2 = 20 = = = = = = = = 84 126 168 210 252 294 336 378 45 × × × × × × × × 3 4 5 6 7 8 9 = = = = = = = 2 3 4 5 6 7 8 9 = = = = = = = = 45 45 45 45 45 45 45 × × × × × × × 3 4 5 6 7 8 9 40 40 40 40 40 40 40 2 3 4 5 6 7 8 9 88 132 176 220 264 308 352 396 18 18 18 18 18 18 18 × × × × × × × 34 51 68 85 102 119 136 153 17 17 17 17 17 17 17 17 × 2 = 42 × × × × × × × × = = = = = = = = × × × × × × × = 48 = 64 = 80 = 96 = 112 = 128 = 144 36 54 72 90 108 126 144 162 3 4 5 6 7 8 9 18 × 2 = × × × × × × × 118 177 236 295 354 413 472 531 42 42 42 42 42 42 42 2 3 4 5 6 7 8 9 87 × 2 = 174 85 85 85 85 85 85 85 16 16 16 16 16 16 16 16 × 2 = 32 = = = = = = = = 122 183 244 305 366 427 488 549 44 × × × × × × × × × × × × × × × 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 = = = = = = = = 44 44 44 44 44 44 44 86 86 86 86 86 86 86 × × × × × × × 85 × 2 = 170 83 83 83 83 83 83 83 83 × 2 = 166 59 59 59 59 59 59 59 2 3 4 5 6 7 8 9 126 189 252 315 378 441 504 567 65 × × × × × × × × 61 × × × × × × × × = = = = = = = = 64 × × × × × × × × 116 174 232 290 348 406 464 522 61 61 61 61 61 61 61 2 3 4 5 6 7 8 9 35 × × × × × × × × = = = = = = = = 120 180 240 300 360 420 480 540 63 × × × × × × × × 34 × × × × × × × × 2 3 4 5 6 7 8 9 = = = = = = = = 63 63 63 63 63 63 63 41 × × × × × × × × 58 58 58 58 58 58 58 2 3 4 5 6 7 8 9 124 186 248 310 372 434 496 558 40 × × × × × × × × 60 × × × × × × × × = = = = = = = = 59 × × × × × × × × 60 60 60 60 60 60 60 2 3 4 5 6 7 8 9 58 × × × × × × × × 62 × × × × × × × × 86 × 2 = 172 84 84 84 84 84 84 84 84 × 2 = 168 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 × × × × × × × 39 39 39 39 39 39 39 82 82 82 82 82 82 82 2 3 4 5 6 7 8 9 82 × 2 = 164 38 38 38 38 38 38 38 62 62 62 62 62 62 62 © Frank Tapson 2004 [trolFG:18] An alternative front cover for 'A Book of Multiplication Tables 10 to 99 Cut out and paste over the existing front cover, before making multiple copies. A Book of Multiplication Tables 10 to 99 © Frank Tapson 2004 [trolFG:19]
© Copyright 2024 Paperzz