1.6
Division
1.6
OBJECTIVES
1. Use the language of division
2. Write a division problem as repeated subtraction
3. Divide whole numbers
We will now examine a fourth arithmetic operation, division. Just as multiplication was repeated addition, division is repeated subtraction. Division asks how many times one number is contained in another.
Example 1
Dividing by Using Subtraction
Joel needs to set up 48 chairs in the student union for a concert. If there is room for 8 chairs
per row, how many rows will it take to set up all 48 chairs?
This problem can be solved by subtraction. Each row subtracts another 8 chairs.
48
8
40
8
32
8
24
8
16
8
8
8
40
32
24
16
8
0
Because 8 can be subtracted from 48 six times, there will be 6 rows.
This can also be seen as a division problem
© 2001 McGraw-Hill Companies
48 8 6
or
6
8B48
or
48
6
8
No matter which method we use, we call the 48 the dividend, the 8 the divisor, and the 6
the quotient.
CHECK YOURSELF 1
Carlotta is creating a garden path made of bricks. She has 72 bricks. Each row will
have 6 bricks in it. How many rows can she make?
71
CHAPTER 1
OPERATIONS ON WHOLE NUMBERS
Units Analysis
When dividing a denominate number by an abstract number, the result will get
the units of the denominate number. Here are a couple of examples
76 trombones 4 19 trombones
$55 11 $5
When one denominate number is divided by another, the result will get the
units of the dividend over the units of the divisor.
144 miles 6 gallons 24 miles/gallon (which we read as “miles per gallon”)
$120 8 hours 15 dollars/hour (“dollars per hour”)
To solve a problem that requires division, you must first set up the problem as a division
statement. The next example will illustrate this.
Example 2
Writing a Division Statement
Write a division statement that corresponds to the following situation. You need not do the
division.
The staff at the Wok Inn Restaurant splits all tips at the end of each shift. Yesterday’s
evening shift collected a total of $224. How much should each of the seven employees get
in tips?
$224 7 employees
(note that the units for the answer will be
“dollars per employee”)
CHECK YOURSELF 2
Write a division statement that corresponds to the following situation. You need
not do the division.
All nine sections of basic math skills at SCC (Sum Community College) are full.
There are a total of 315 students in the classes. How many students are in each class?
What are the units for the answer?
In the previous section, we used a rectangular array of stars to represent multiplication.
These same arrays can represent division. Just as 3 4 12 and 4 3 12, so is it true
that 12 3 4 and 12 4 3.
© 2001 McGraw-Hill Companies
72
DIVISION
4 3 12
73
3 4 12
SECTION 1.6
or
12 3 4
or
12 4 3
This relationship allows us to check our division results by doing multiplication.
Example 3
Checking Division by Using Multiplication
NOTE For a division problem
to check, the product of the
divisor and the quotient must
equal the dividend.
3
(a) 7B21
Check: 7 3 21
(b) 48 6 8
Check: 6 8 48
CHECK YOURSELF 3
Complete the division statements, and check your results.
(b) 28 7 (a) 9B45
NOTE Because 36 9 4, we
say that 36 is exactly divisible
by 9.
In our examples so far, the product of the divisor and the quotient has been equal to the
dividend. This means that the dividend is exactly divisible by the divisor. That is not always
the case. Let’s look at another example using repeated subtraction.
Example 4
Dividing by Using Subtraction, Leaving a Remainder
How many times is 5 contained in 23?
NOTE Notice that the
remainder must be smaller than
the divisor or we could subtract
again.
23
5
18
18
5
13
13
5
8
8
5
3
We see that 5 is contained 4
times in 23, but 3 is “left over.”
© 2001 McGraw-Hill Companies
23 is not exactly divisible by 5. The “left over” 3 is called the remainder in the division.
To check the division operation when a remainder is involved, we have the following
rule:
Definitions: Remainder
Dividend divisor quotient remainder
CHECK YOURSELF 4
How many times is 7 contained in 38?
74
CHAPTER 1
OPERATIONS ON WHOLE NUMBERS
Example 5
Checking Division by a Single-Digit Number
Using the work of the previous example, we can write
NOTE Another way to write
the result is
4
5B23
4 r3 The “r” stands for
5B23
remainder.
To apply our previous rule, we have
with remainder 3
Divisor
Dividend
23 5 4 3
Remainder
23 20 3
23 23
The division checks.
CHECK YOURSELF 5
Evaluate 7B 38. Check your answer.
We must be careful when 0 is involved in a division problem. There are two special
cases.
Rules and Properties:
Division and Zero
1. 0 divided by any whole number (except 0) is 0.
2. Division by 0 is undefined.
The first case involving zero occurs when we are dividing into zero.
Example 6
Dividing into Zero
0 5 0 because 0 5 0.
CHECK YOURSELF 6
(a) 0 7 (b) 0 12 Our second case illustrates what happens when 0 is the divisor. Here we have a special
problem.
Example 7
Dividing by Zero
8 0 ? This means that 8 0 ?
Can 0 times some number ever be 8? From our multiplication facts, the answer is no! There
is no answer to this problem, so we say that 8 0 is undefined.
© 2001 McGraw-Hill Companies
NOTE Notice that the
multiplication is done before
the 3 is added.
Quotient
DIVISION
SECTION 1.6
75
CHECK YOURSELF 7
Decide whether each problem results in 0 or is undefined.
(a) 9 0
(b) 0 9
(c) 0 15
(d) 15 0
It is easy to divide when small whole numbers are involved, because much of the work can
be done mentally. In working with larger numbers, we turn to a process called long division. This is a shorthand method for performing the steps of repeated subtraction.
To start, let’s look at an example in which we subtract multiples of the divisor.
Example 8
NOTE With larger numbers,
repeated subtraction is just too
time-consuming to be practical.
Dividing by a Single-Digit Number
Divide 176 by 8.
Because 20 eights are 160, we know that there are at least 20 eights in 176.
Step 1 Write
20 eights
20
8B176
160
16
Subtracting 160 is just a shortcut for
subtracting eight 20 times.
After subtracting the 20 eights, or 160, we are left with 16. There are 2 eights in 16, and so
we continue.
Step 2
2 eights
2
20 22
8B176
160
16
16
0
Adding 20 and 2 gives us the quotient, 22.
Subtracting the 2 eights, we have a 0 remainder. So 176 8 22
CHECK YOURSELF 8
Verify the results of Example 8, using multiplication.
© 2001 McGraw-Hill Companies
The next step is to simplify this repeated-subtraction process one step further. The result
will be the long-division method.
Example 9
Dividing by a Single-Digit Number
Divide 358 by 6.
The dividend is 358. We look at the first digit, 3. We cannot divide 6 into 3, and so we look
at the first two digits, 35. There are 5 sixes in 35, and so we write 5 above the tens digit of
the dividend.
5
6B358
When we place 5 as the tens digit,
we really mean 5 tens, or 50.
76
CHAPTER 1
OPERATIONS ON WHOLE NUMBERS
Now multiply 5 6, place the product below 35, and subtract.
5
6B358
300
5
We have actually subtracted 50 sixes
(300) from 358.
Because the remainder, 5, is smaller than the divisor, 6, we bring down 8, the ones digit of
the dividend.
5
6B358
300
58
Now divide 6 into 58. There are 9 sixes in 58, and so 9 is the ones digit of the quotient. Multiply 9 6 and subtract to complete the process.
NOTE Because the 4 is smaller
than the divisor, we have a
remainder of 4.
NOTE Verify that this is true
59
6B358
30
58
54
4
We now have:
358 6 59 r4
To check: 358 6 59 4
and that the division checks.
CHECK YOURSELF 9
Divide 7B 453.
Long division becomes a bit more complicated when we have a two-digit divisor. It is now
a matter of trial and error. We round the divisor and dividend to form a trial divisor and a
trial dividend. We then estimate the proper quotient and must determine whether our estimate was correct.
Example 10
Dividing by a Two-Digit Number
Divide
7
NOTE Think: 4B29
Round the divisor and dividend to the nearest ten. So 38 is rounded to 40, and 293 is
rounded to 290. The trial divisor is then 40, and the trial dividend is 290.
Now look at the nonzero digits in the trial divisor and dividend. They are 4 and 29. We
know that there are 7 fours in 29, and so 7 is our first estimate of the quotient. Now let’s see
if 7 works.
7
38B293
266
27
Your estimate
Multiply 7 38. The product, 266, is
less than 293, and so we can subtract.
The remainder, 27, is less than the divisor, 38, and so the process is complete.
293 38 7 r27
Check: 293 38 7 27
You should verify that this statement is true.
© 2001 McGraw-Hill Companies
38B293
DIVISION
SECTION 1.6
77
CHECK YOURSELF 10
Divide.
57B482
Because this process is based on estimation, we can’t expect our first guess to always be
right.
Example 11
Dividing by a Two-Digit Number
Divide
8
NOTE Think: 5B 43
54B428
Rounding to the nearest ten, we have a trial divisor of 50 and a trial dividend of 430.
Looking at the nonzero digits, how many fives are in 43? There are 8. This is our first estimate.
8
54B428
432
Too large
We multiply 8 54. Do you see what’s wrong? The
product, 432, is too large. We can’t subtract. Our
estimate of the quotient must be adjusted downward.
We adjust the quotient downward to 7. We can now complete the division.
7
54B428
378
50
We have
428 54 7 r50
Check: 428 54 7 50
CHECK YOURSELF 11
Divide.
© 2001 McGraw-Hill Companies
63B557
We have to be careful when a 0 appears as a digit in the quotient. Let’s look at an example in which this happens with a two-digit divisor.
Example 12
NOTE Our divisor, 32, will
divide into 98, the first two
digits of the dividend.
Dividing with Large Dividends
Divide
32B9871
CHAPTER 1
OPERATIONS ON WHOLE NUMBERS
Rounding to the nearest ten, we have a trial divisor of 30 and a trial dividend of 100. Think,
“How many threes are in 10?” There are 3, and this is our first estimate of the quotient.
3
32B9871
96
2
Everything seems fine so far!
Bring down 7, the next digit of the dividend.
30
32B9871
96
27
Now do you see the difficulty? We cannot divide
32 into 27, and so we place 0 in the tens place
of the quotient to indicate this fact.
We continue by multiplying by 0. After subtraction, we bring down 1, the last digit of the
dividend.
30
32B9871
96
27
00
271
Another problem develops here. We round 32 to 30 for our trial divisor, and we round 271
to 270, which is the trial dividend at this point. Our estimate of the last digit of the quotient
must be 9.
309
32B9871
96
27
00
271
288
Too large
We can’t subtract. The trial quotient must be adjusted downward to 8. We can now complete
the division.
308
32B9871
96
27
00
271
256
15
9871 32 308 r15
Check: 9871 32 308 15
CHECK YOURSELF 12
Divide.
43B8857
© 2001 McGraw-Hill Companies
78
DIVISION
SECTION 1.6
79
Because of the availability of the handheld calculator, it is rarely necessary that people find
the exact answer when performing long division. On the other hand, it is frequently important that one be able to either estimate the result of long division, or confirm that a given
answer (particularly from a calculator) is reasonable. As a result, the emphasis in this section will be to improve your estimation skills in division.
Let’s divide a four-digit number by a two-digit number. Generally, we will round the
divisor to the nearest ten and the dividend to the nearest hundred.
Example 13
Estimating the Result of a Division Application
The Ramirez family took a trip of 2394 miles (mi) in their new car, using 77 gallons (gal)
of gas. Estimate their gas mileage (mi/gal).
Our estimate will be based on dividing 2400 by 80.
30
80B2400
They got approximately 30 mi/gal.
CHECK YOURSELF 13
Troy flew a light plane on a trip of 2844 mi that took 21 hours (h). What was his
approximate speed in miles per hour (mi/h)?
As before, we may have to combine operations to solve an application of the mathematics you have learned.
Example 14
Estimating the Result of a Division Application
Charles purchases a new car for $8574. Interest charges will be $978. He agrees to make
payments for 4 years. Approximately what should his payments be?
First, we find the amount that Charles owes:
$8574 $978 $9552
© 2001 McGraw-Hill Companies
Now, to find the monthly payment, we divide that amount by 48 (months). To estimate the
payment, we’ll divide $9600 by 50 months.
192
50B9600
The payments will be approximately $192 per month.
CHECK YOURSELF 14
One $10 bag of fertilizer will cover 310 square feet. Approximately what would it
cost to cover 2200 square feet?
CHAPTER 1
OPERATIONS ON WHOLE NUMBERS
CHECK YOURSELF ANSWERS
1. 12
2. 315 students 9 classes; students per class
3. (a) 5; 9 5 45;
(b) 4; 7 4 28
4. 5
5. 5 with remainder 3
6. (a) 0; (b) 0
7. (a) undefined; (b) 0; (c) 0; (d) undefined
8. 8 22 176
9. 64 with remainder 5
10. 8 with remainder 26
11. 8 with remainder 53
12. 205 with remainder 42
13. 140 mi/h
14. $70
© 2001 McGraw-Hill Companies
80
Name
1.6
Exercises
Section
Date
1. If 48 8 6, 8 is the _______, 48 is the _______, and 6 is the _______.
9
2. In the statement 5B45 , 9 is the _______, 5 is the _______, and 45 is the _______.
3. Find 36 9 by repeated subtraction.
ANSWERS
1.
4. Find 40 8 by repeated subtraction.
2.
5. Stefanie is planting rows of tomato plants. She wants to plant 63 plants with 9 plants
per row. How many rows will she have?
3.
4.
5.
6.
7.
8.
9.
10.
11.
6. Nick is designing a parking lot for a small office building. He must make room for
12.
42 cars with 7 cars per row. How many rows should he plan for?
13.
Divide the following. Identify the correct units for the quotient.
7. 36 pages 4
14.
8. $96 8
9. 4900 km 7
10. 360 gal 18
11. 160 miles 4 hours
12. 264 ft 3 sec
13. 3720 hours 5 months
14. 560 calories 7 grams
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
© 2001 McGraw-Hill Companies
Divide using long division, and check your work.
15. 54 9
16. 21 3
17. 6B42
18. 7B63
19. 4B32
20. 56 8
21. 5B43
22. 40 9
23. 9B65
24. 6B 51
25. 57 8
26. 74 8
27. 0 5
28. 5 0
29. 4 0
30. 0 12
31. 0 6
32. 18 0
29.
30.
31.
32.
81
ANSWERS
33.
Divide.
34.
33. 5B83
34. 9B78
35. 3B162
36. 4B232
37. 8B293
38. 7B346
39. 8B3136
40. 5B4938
41. 8B5438
42. 9B3527
43. 8B22,153
44. 5B43,287
45. 4B4351
46. 8B3251
47. 4B7321
48. 7B8923
49. 3B13,421
50. 4B34,093
51. 48B892
52. 54B372
53. 23B534
54. 67B939
55. 45B2367
56. 53B3480
57. 34B8748
58. 27B9335
59. 42B7902
60. 53B8729
61. 28B8547
62. 38B7892
63. 763B3071
64. 871B4321
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
Solve the following applications.
50.
65. Counting. Ramon bought 56 bags of candy. There were 8 bags in each box. How
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
82
many boxes were there?
66. Capacity. There are 32 students who are taking a field trip. If each car can hold
4 students, how many cars will be needed for the field trip?
67. Packaging. There are 63 candy bars in 7 boxes. How many candy bars are in each
box?
© 2001 McGraw-Hill Companies
51.
68. Business. A total of 54 printers were shipped to 9 stores. How many printers were
shipped to each store?
69. Recreation. Joaquin is putting pictures in an album. He can fit 8 pictures on each
page. If he has 77 pictures, how many will be left over after he has filled the last
8-picture page?
70. Counting. Kathy is separating a deck of 52 cards into 6 equal piles. How many cards
will be left over?
71. Recreation. Ticket receipts for a play were $552. If the tickets were $4 each, how
many tickets were purchased?
72. Construction. Construction of a fence section requires 8 boards. If you have 256
boards available, how many sections can you build?
73. Business. The homeowners along a street must share the $2030 cost of new street
© 2001 McGraw-Hill Companies
lighting. If there are 14 homes, what amount will each owner pay?
74. Cost. A bookstore ordered 325 copies of a textbook at a cost of $7800. What was the
cost to the store for an individual textbook?
ANSWERS
75.
75. Telephone calls. The records of an office show that 1702 calls were made in 1 day. If
there are 37 phones in the office, how many calls were placed per phone?
76.
77.
76. Television costs. A television dealer purchased 23 sets, each the same model, for
$5267. What was the cost of each set?
78.
77. Computers. A computer printer can print 340 lines per minute (min). How long will
79.
it take to complete a report of 10,880 lines?
78. Distance. A train traveled 1364 mi in 22 h. What was the speed of the train?
Hint: Speed is the distance traveled divided by the time.
80.
81.
82.
79. Bonuses. A company distributes $16,488 in year-end bonuses. If each of the 36
83.
employees receives the same amount, what bonus will each receive?
84.
80. Complete the following number cross.
Down
1. (12 + 16) 2
2. 67 3
4. 744 12
5. 2600 13
7. 6300 12
10. 304 2
11. 5 (161 7)
13. 9027 17
15. 400 20
17. 9 5
1
2
3
7
6
14
18
8
13
12
15
5
10
9
11
4
17
16
19
Estimate the result in the following division problems. (Remember to round divisors to
the nearest ten and dividends to the nearest hundred.)
84
81. 810 divided by 38
82. 458 divided by 18
83. 4967 divided by 96
84. 3971 divided by 39
© 2001 McGraw-Hill Companies
Across
1. 48 4
3. 1296 8
6. 2025 5
8. 4 5
9. 11 11
12. 15 3 111
14. 144 (2 6)
16. 1404 6
18. 2500 5
19. 3 5
ANSWERS
85. 8971 divided by 91
86. 3981 divided by 78
85.
86.
87. 3879 divided by 126
88. 8986 divided by 178
89. 3812 divided by 188
90. 5245 divided by 255
87.
88.
89.
Solve the following applications.
91. Gas mileage. Jose drove 279 miles (mi) on 18 gallons of gas. Estimate his mileage.
(Hint: Find the number of miles per gallon.)
92. Construction. A contractor can build a house in 27 days. Estimate how many houses
90.
91.
92.
can be built in 265 days.
93.
93. Inheritances. Twelve people are to share equally in an estate totaling $26,875.
Estimate how much money each person will receive.
94.
95.
94. Business. There is $365 left in the budget to purchase pens. If each box of pens costs
$18, estimate the number of boxes of pens that can be ordered.
95. Monthly payments. Tara purchased a used car for $1850 by paying $275 down and
the rest in equal monthly payments over a period of 18 months. Estimate the amount
of her monthly payments.
96.
97.
98.
96. Consumer purchases. Art has $275 to spend on shirts. If the cost of a shirt is $23,
estimate the number of shirts that Art can buy.
97. You are going to recarpet your living room. You have budgeted $1500 for the carpet
© 2001 McGraw-Hill Companies
and installation.
(a) Determine how much carpet you will need to do the job. Draw a sketch to
support your measurements.
(b) What is the highest price per square yard you can pay and still stay within
budget?
(c) Go to a local store and determine the total cost of doing the job for three different
grades of carpet. Be sure to include padding, labor costs, and any other expenses.
(d) What considerations (other than cost) would affect your decision about what type
of carpet to install?
(e) Write a brief paragraph indicating your final decision, and give supporting
reasons.
98. Division is the inverse operation of multiplication. Many daily activities have
inverses. For each of the following activities, state the inverse activity:
(a)
(b)
(c)
(d)
Spending money
Going to sleep
Turning down the volume on your CD player
Getting dressed
85
ANSWERS
99. If you have no money in your pocket and want to divide it equally among your four
99.
friends, how much does each person get? Use this situation to explain division of
zero by a nonzero number.
100.
100. Explain the difference between division by zero and division of zero by a natural
number.
101.
101. Division is not associative. For example, 8 4 2 will produce different results
102.
if 8 is divided by 4 and then divided by 2 or if 8 is divided by the result of 4 2.
In the following, place parentheses in the proper place so that the expression is
true.
103.
(a) 16 8 2 4
(b) 16 8 2 1
(c) 125 25 5 1
(d) 125 25 5 25
(e) Is there any situation in which the order of how the operation of division is
performed produces the same result? Give an example.
102. Division is not commutative. For example, 15 5 5 15. What must be true of
the numbers a and b if a b b a?
103. Your class goes to a local amusement park. A ride can carry 15 passengers in each
cycle.
(a) If a new cycle starts every 5 min, how many cycles does the ride make every
hour?
(b) How many passengers can ride every hour?
(c) How long would it take all the students in your class to complete the ride?
1. Divisor, dividend, quotient
3. 4
5. 7
7. 9 pages
9. 700 km
11. 40 miles/hour
13. 744 hours/month
15. 6
17. 7
19. 8
21. 8 r3
23. 7 r2
25. 7 r1
27. 0
29. Undefined
31. 0
33. 16 r3
35. 54
37. 36 r5
39. 392
41. 679 r6
43. 2769 r1
45. 1087 r3
47. 1830 r1
49. 4473 r2
51. 18 r28
53. 23 r5
55. 52 r27
57. 257 r10
59. 188 r6
61. 305 r7
63. 4 r19
65. 7 boxes
67. 9 bars
69. 5 pictures
71. 138 tickets
73. $145
75. 46 calls
77. 32 min
79. $458
81. 20
83. 50
85. 100
87. 30
89. 20
91. 15 mi/gal
93. $2700
95. $80
97.
99.
101.
103.
86
© 2001 McGraw-Hill Companies
Answers
Using a Scientific Calculator
to Divide
Of course, division is easily done by using your calculator. However, as we will see, some
special things come up when we use a calculator to divide. First let’s outline the steps of
division as it is done on a calculator.
Divide 35B2380.
1. Enter the dividend.
2380
2. Press the divide key.
3. Enter the divisor.
35
4. Press the equals key.
The desired quotient is now in
your display.
The display shows 68
We mentioned some of the difficulties related to division with 0 earlier. Let’s experiment
on the calculator.
Example 1
Using a Scientific Calculator to Divide
To find 0 5, we use this sequence:
0 5 Display
0
There is no problem with this. Zero divided by any whole number other than 0 is just 0.
CHECK YOURSELF 1
What is the result when you use your calculator to perform the following operation?
© 2001 McGraw-Hill Companies
0 17
We’ve seen what happens when dividing zero by another number, but what happens
when we try to divide by zero? More importantly to this section, how does the calculator
handle division by zero? Example 2 illustrates this concept.
87
88
CHAPTER 1
OPERATIONS ON WHOLE NUMBERS
Example 2
Using a Scientific Calculator to Divide
To find 5 0, we use this sequence:
5 0 Display
NOTE You may find that you
must “clear” your calculator
after trying this.
Error
If we try this sequence, the calculator gives us an error! Do you see why? Division by 0 is
not allowed. Try this on your calculator to see how this error is indicated.
CHECK YOURSELF 2
What is the result when you use your calculator to perform the following operation?
17 0
Another special problem comes up when a remainder is involved in a division problem.
Example 3
Using a Scientific Calculator to Divide
In a previous section, we divided 293 by 38 and got 7 with remainder 27.
293 38 7.7105263
Quotient
Remainder
7 is the whole-number part of the
quotient as before.
0.7105263 is the decimal form of the
remainder, 27, as a fraction of 38.
CHECK YOURSELF 3
What is the result when you use your calculator to perform the following operation?
458 36
The calculator can also help you combine division with other operations.
Example 4
Using a Scientific Calculator to Divide
To find 18 2 3, use this sequence:
18 2 3 Display
12
Do you see that the calculator has
done the division as the first step?
© 2001 McGraw-Hill Companies
this later. For now, just be
aware that the calculator will
not give you a remainder in the
form we have been using in this
chapter.
NOTE We will say more about
DIVISION
CHECK YOURSELF 4
Use your calculator to compute.
15 5 7
Example 5
Using a Scientific Calculator to Divide
To find 6 3 2, use this sequence:
6 3 2 Display
4
CHECK YOURSELF 5
Use your calculator to compute.
18 6 5
CHECK YOURSELF ANSWERS
© 2001 McGraw-Hill Companies
1. 0
2. Error message
3. 12.72222
4. 10
5. 15
SECTION 1.6
89
Name
Section
Calculator Exercises
Date
Use your calculator to perform the indicated operations.
ANSWERS
1. 5940 45
2. 2808 36
3. 36,182 79
4. 36,232 56
5. 583,467 129
6. 464,184 189
7. 6 9 3
8. 18 6 3
9. 24 6 4
10. 32 8 4
1.
2.
3.
4.
5.
6.
7.
8.
9.
11. 4368 56 726 33
12. 1176 42 1572 524
13. 3 8 8 8 12
14. 5 6 6 18
15. (18 87) 15
16. (89 14) 25
10.
11.
12.
13.
14.
15.
Answers
16.
1. 132
15. 7
5. 4523
7. 9
9. 16
11. 100
13. 128
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