1
2
Unit 1
Whole numbers
Activity 1
1. Copy and complete each number pattern.
2 671
13 450
25 125
124 300
180 500
2 680
13 650
25 000
2 689
14 450
24 875
126 300
128 300
180 000
179 500
2. Write these words as numbers.
a. five hundred and twelve thousand four hundred and seventy
b. one hundred and fifty seven thousand eight hundred and thirteen
c. two hundred and sixty two thousand six hundred and nineteen
d. eight hundred and seventy nine thousand and nine
3. Write these numbers in words.
a. 178 465
b. 342 084
c. 267 585
d. 572 749
e. 245 698
f. 153 769
g. 845 701
h. 899 499
3
4. Place Value
Example
12 6
Hundred
Thousand
Ten
3 1 5
Thousand
Hundred
Ten
Unit
Thousand
What is the value of the 7 in these numbers?
a. 872 164
b. 280 178
c. 128 317
d. 547 812
e. 725 106
f.
569 782
g. 509 798
h. 738 526
5. Compare these numbers. Use < ; > or =.
a. 347 852
347 825
b. 632 119
631 119
c. 585 258
585 528
d. 941 787
914 787
e. 446 664
446 646
f. 202 220
220 202
6. Arrange these numbers from biggest to smallest.
a. 145 625; 154 625; 154 652; 145 265; 145 652
b. 730 919;
c. 70 007;
730 199;
70 770;
730 991; 731 999; 730 999
70 077;
70 707; 70 070
Underline
odd numbers.
4
7. Rounding off to the nearest 5, 10, 100 and 1 000.
Remember the rule for rounding off to the nearest 5:
0
1
2
3
4
1 and 2 are closer to 0 than 5
5
3 and 4 are closer to 5 than 0
14≈15
27≈25
6
7
8
9
10
6 and 7 are closer to 5 than to 10
8 and 9 are closer to 10 than to Examples:
39≈40
91≈90
Copy and complete the table by rounding off to the number shown.
5
725 146
Example
725 145
10
100
1 000
725 150
725 100
725 000
a. 651 847
b. 361 705
c. 280 663
d. 419 258
e. 118 306
8. Prime Numbers
A prime number has only 2 factors:
the number itself and 1
So, 5 must be a prime
number, because only 5 and 1
divide into 5 exactly.
That’s right! So, nine is not a prime number as
it has more than 2 factors: 1, 3 and 9.
5
Write down the prime numbers, in your book.
7
9
15
17
25
23
27
24
18
33333
97
93
91
99
95
Activity 2
Properties of numbers
Copy and complete the following problems in your workbook
1. Additive property of 0
73 + 0 = 73
73 – 0 =73
a) 1415 + 0 =
1415 – 0 =
b) 657 +
657 -
= 657
c)
+2784= 2784
d)378 + 0 =
= 657
e)9451+
- 2784 = 0
378 – 0
= 9451 9451 -
2. Add and subtract the same number
315+65-65=315
c.4 554+200-
=4 554
a.4 785+212-212=
d.8 760-450+450=
b.3 151-2 451+2 451=
e.
+456-456=7 019
3. Multiplicative property of 1
72x1=72
72÷1=72
c.370x
a.456x1=
d.4 384÷
b.5 716÷1=
e.
=370
=1
÷636=1
=0
6
4. Multiply and divide by the same number
72÷9x9=72
c.
÷10x10=76
a.625÷25x25=
d.130x
b.25x10÷
e.84÷12x
=25
÷12=130
=84
5. Inverse operations
24+40=64 therefore 64-40=24
7x8=56 therefore 56÷8=7
a.387-80=
so 80+307=
e.30x3=
so 90÷3=
b.65+125=
so
f.240÷6=
so 40x6=
190-65=
c.2 500+600=
so 3 100-600=
g.9x1 000=
d.4 500-1 200=
so 1 200=3 300=
h.1 200÷40=
Activity 3
so 9 000÷9=
so 40x30=
Remember:
Brackets mean ‘Do that part first.’
Flow charts
1. Copy and complete the tables.
a.
Number 1
X5 +2
2
3
5
10
20
100
2
3
5
10
20
100
2
3
5
10
20
100
2
3
5
10
20
100
2
3
5
10
20
100
b.
Number 1
+5 x2
c.
Number 1
(x10)÷1
d.
Number 1
x3 +15
e.
Number 1
(+15)x3
7
2. Copy and complete each flow diagram.
x9
+13
+9
-150
x100
Activity 4
Problem Solving
1. Solve the following equations.
a. (3x4)÷3=
b. 12x(2+4)=
c. 25+(10x5)=
d. 9+8-6=
e. (8x6)÷2=
f. 8-(24÷4)=
g. (3+5)x(9-2)=
h. 6x(7-3)=
i. (81÷9)x4=
Remember these rules we learned in Grade 5.
Commutative Law
When you add and multiply: you can swap numbers around and still get the same answer.
Examples
3+1=1+3
and
2x4=4x2
8
Associative Law
When you add or multiply: it does not matter how you group the numbers
Examples
1+(2+3)=(1+2)+3
and
2x(3x4)=(2x3)x4
Determine whether the following are equal to each other.
Fill in = if they are the same and ≠ if they are not equal.
Copy and complete.
Examples
3x2≠3+2
4x5=5x4
3+6
6+3
g.
2x(6x7)
(2x6)x7
a.
b.
12-4
4-12
h.
15+12
15-12
c.
2+(6x3)
i.
12+(10+1)
d.
(15+20)+5
j.
10x1
e.
(10÷5)x2
k.
752-0
f.
(6+1)x6
l.
(70÷10)x5
(2+6)x3
15+(20+5)
10+(5x2)
(6x1)+6
(12+10)÷1
10÷1
752+0
70x(10÷5)
3. Write a number sentence for each word problem. Calculate the answer.
a. Sizwe has 85 packets of sweets to sell. If he sells 30 packets on Monday and 43
packets on Tuesday, how many packets does he have left to sell?
b. If Sizwe sells all his packets of sweets for R20 a packet, how much money did he
get all together?
9
Unit 2
Addition and subtraction (5 digit numbers)
Activity 1
Working with 5 digit numbers
It is important to know place value before
we + and – 5 digit numbers.
Ten
Thousand
Thousand
Hundred
Tens
Units
TH
H
T
U
5
4
2
7
400
200
7
TTH
3
30 000
5 000
35 427
1. Write each number in expanded notation.
Number
98 304`
32 345
45 689
63 047
16 693
Expanded Notation
90 000+ 8 000+ 300+ 4
Example
10
2. Copy and complete the number lines.
a.
73 500
73 400
73 300
13 250
12 250
11 250
49 000
49 500
b.
c.
48 00
3. Write the pairs of numbers that make up 10 000
6 500
7 045
7 610
4 268
8 250
8 050
1 750
5 732
3 500
1 950
2 390
2 955
Activity 2
Mental addition and subtraction
1. Copy and complete the table
2.
a
b
c
d
e
Number
42 389
76 381
24 123
45 002
37 984
Add 10
Add 100
Add 1 000
Add 10 000
Subtract 100
Subtract
1 000
Subtract
10 000
2. Copy and complete the table.
a
b
c
d
e
Number
18 294
17 581
14 590
16 900
20 030
Subtract 10
11
3 a. Write the numbers from smallest to biggest
88 888
88 808
80 888
88 088
88 880
77 707
77 077
b. Write the numbers from largest to smallest
70 777
77 770
77 777
4. Supermarkets buy boxes of jelly beans in large bottles. Each small coloured block
represents 1 bottle. 1 bottle holds 1 000 jelly beans. Calculate (work out) how many
jelly beans there would be in each box.
a
b
c
Activity 3
Rounding off to the nearest 10 000
If the thousands digit is 0 1 2 3 or 4,
round off the number to the lower 10
Examples:
22 450≈20 000
10 100≈10 000
44 499≈40 000
83 386≈80 000
If the thousands digit is 5 6 7 8 or 9, round off the
number to the higher 10 000
12
Examples:
77 500≈80 000
95 000≈100 000
46 999≈50 000
88 001≈90 000
Complete the table
Number
58 326
75 899
17 453
22 126
46 268
a
b
c
d
e
≈ to nearest 100
Activity 4
Addition of 5 digit numbers
Different methods can be used to add:
Method 1:
29 465+ 19 076=?
29 465 = 20 000 + 9 000 + 400 + 60 + 5
+ 19 076 = 10 000 + 9 000 +
0 + 70 + 6
= 30 000 + 18000 + 400 + 130 + 11
= 40 000 + 8 000 + 500 + 40 + 1
= 48 541
Method 2:
1
1
1
1
47 897
+32 139
80 036
1. Round off and calculate
≈ to nearest 1 000
≈ to nearest 10 000
13
Number
Round off to nearest
10 000 and add
Calculate actual
answer using the
method you prefer
Example:
29 018 + 44 587
30 000+ 40 000
=70 000
29 018
+44 587
73 605
a
19 742 + 15 348
b
29 364 + 27 243
c
16 239 + 35 627
d
35 453 + 13 752
e
18 235 + 17 194
f
22 587 + 14 936
2. Word problems:
a. A car salesman has sold 2 cars today. If the first car costs R46 938 and the second
car costs R65 235, how much money has he made today?
b. How much money is raised if Tom Newby makes R32 485 on Great Race Day and
R19 327 on Entrepreneurs Day?
c. If Mrs. Smith works over time, she earns R3 550 more than her usual salary of
R 11380. How much did Mrs. Smith earn between New Year’s Day and 31 March?
14
Activity 5
Subtraction of 5 digit numbers
There are different methods that one can use to subtract:
Method 1:
89 735-47 618=?
80 000 + 9 000 + 700 + 30 + 5
- 40 000 + 7 000 + 600 + 10 + 8
becomes
80 000 + 9 000 + 700 + 20 + 15
- 40 000 + 7 000 + 600 + 10 + 8
=
42 117
40 000 + 2 000 +100 + 10 + 7
Method 2:
-
1
8 9
7 2 1
5 2
1 1 6
3 7
6 0 5
1. Round off and subtract.
Number
Round off to nearest
10 000 and subtract
Example
67 890 - 52 786
70 000-50 000= 20 000
a.
b.
c.
d.
e.
f.
87 256 - 34 398
73 524 - 35 297
26 472 - 13 561
65 965 - 31 398
43 560 - 4 397
58 439 - 6 375
Actual answer using the
method you prefer
67 890
- 52 786
15 104
15
R75 950
2. Word problems
a.
The price of the car has been reduced by R7 890.
What is the price of the car now?
b.
A concert is attended by 63 750 people.
If 29 826 people arrived by car, how many people used another form of
transport?
c.
Shane won R90 000 in the Lotto.
After spending R44 587, how much did he have left?
Activity 6
Addition and subtraction of 5 digit numbers
1. Copy and complete the table.
Add 7 000
a
b
c
d
e
Minus 4 000
Add 50 000
Minus 20 000
20 000
25 000
43 500
38 250
28 325
2. Rapid recall.
11 250+?=12 000
30 450+?=35 000
15 000-?=14 500
12 500+?=13 000
19 200+?=21 000
19 000-?=17 300
14 350+?=15 000
16 400+?=16 750
20 500-?=15 000
See how
15 490+?=16 000
15 850+?=17 000
22 250-?=21 000
quickly you
42 300+?=50 000
27 125+?=28 000
16 300-?=15 800
can do
35 50+?=37 000
these!
11 000-?=10 100
13 450-?=12 500
16
3. Word Problems
a. 12 396 people visited Freedom Park this year. That is 3 625 more than last year.
How many people visited Freedom Park last year?
b. Three important soccer matches were played at our stadium.
The first was attended by 32 520 spectators, the second by 39 355 spectators and the
third was attended by 27 498 spectators.
How many people attended the matches altogether?
c. Adding 46 705 to a certain number gives you 88 808.
What is the number?
Activity 7
Using inverse operations to check answers
Remember, you can use subtraction to
check your addition calculations and you
can use addition to check your subtraction.
Example:
81 952
-
Check:
11 301
70 651
+ 70 651
11 301
81 952
1. Calculate, then check your answer by using the inverse operation.
a. 35 294+ 13 531
b. 43 565+ 21 899
c. 27 432+ 11 587
d. 24 374- 18 147
e. 41 532- 30 698
f. 38 205- 6 956
g. 13 054+ 11 943
h. 24 567+ 13 418
i. 17 643+ 13 674
j. 52 635-34 396
k. 42 763- 3 897
l. 18 426- 12 757
2. Word problems.
a. The sum of 4 numbers is 12 038.
If three of the numbers are 3 192, 2 774 and 4 008, what is the fourth number?
b. The sum of four numbers is 13 520.
What is the fourth number if three of them are 1 560,4 255 and 6 500?
17
c. If I halve a number, I get 7 432.
What is the number?
d. If I double a number, I get 30 550.
What number did I double?
e. If I add 5 736 to a secret number, I get 9 900.
What is the secret number?
f. If I subtract 3 950 from a number, I get12 300.
What number did I start with?
Activity 8
Assessment of Whole Numbers
1. Use the numbers in the shapes to write 5 numbers.
•
•
•
Each number should have 6 digits.
Your number should be between 200 000 and smaller than 700 000.
You may use each digit only once.
7
5
1
0
3
9
2. Arrange your numbers from smallest to largest.
3. Write the even numbers in green. What makes these numbers even?
4. Write the odd numbers in blue. Why are these numbers odd?
5. Write these numbers in words:
a. 159 487
b. 146 793
c. 645 013
d. 107 209
6. Copy and complete the table.
Round off to Round off to Round off to Round off to
nearest 5
nearest 10
nearest 100
nearest 1 000
a.
156 408
b.
429 731
c.
506 992
18
7. Copy and complete the table.
Equation
X6 +3
(+7) x2
X7 ÷1
(+5) x10
a.
b.
c.
d.
4
27
22
2
3
5
10
20
50
100
8. Say whether the following are = or ≠.
a. 12+10?10+12
b. (10÷2)x5?10÷(2x5)
c. 15x1?15÷1
d. 3+(3x4)?(3+3)x4
e. (6+4)+5?6+(5+4)
f. 8x(3x9)?(8x3)x9
9. Add and subtract.
a.
b.
Calculation
435 254 + 54 678
435 254 – 54 678
Round off to nearest
10 000. Add.
Work out actual answer.
10. Calculate and check your answer by subtracting.
a. 24 567 + 13 418
b. 53 819 + 14 027
Check your work
carefully!
19
Mental Maths. Sheet 1.
Monday
Wednesday
Thursday
Friday
4 834 - □ = 4 414
9 750 - 400
467 + 1 420
Tuesday
Round off to
the nearest
10
2 764 - □ = 2 104
4 500 - 1 250
Replace * with
> or <
875 + 1 115
23156
3 456 - □ = 3 050
6 200 - 800
62 312 * 62 132
4 208 + 1 550
42852
7 827 - □ = 7 117
7 000 - 4 500
19 115 * 19 111
2 632 + 326
80193
5 463 - □ = 5 223
8 450 - 1 400
29 169 * 29 156
4 123 + 1 321
12559
3 876 - □ = 3 110
3 640 - 3 140
73 131 * 73 331
3 050 + 670
65157
4 631 - □ = 2 531
8 125 - 7 100
40 004 * 40 040
2 340 + 1 620
22092
9 215 - □ = 5 100
5 425 - 3 025
54 545 * 54 455
548 + 1 450
39989
Write the number
4 200 - 2 200
23 232 * 23 223
826 + 7 050
300 + 60 000 + 4 + 10
1 350 - 650
61 234 * 61 243
9 000 + 3 + 5 000 + 10
3 040 - 540
84 484 * 84 848
2 456 + 540
92406
Round off to
the nearest
100
6 + 30 000 + 50 + 800
6 400 - 4 500
99 909 * 99 990
225 + 1 800
514 189
200 + 90 + 30 000 + 4
3 100 - 3 000
Place value
908 + 2090
26 924
20 + 9 + 10 000 + 600
2 100 - 150
15̲6 987
2 515 + 1 085
391 971
70 000 + 100 + 9 + 40
3 025 - 225
3̲26 876
6 142 + 2 646
126 086
6 + 3 000 + 40 000
7 100 - 4 000
383 2̲06
1 735 + 4 065
517 852
4 000 + 9 + 70 + 8 000
2 525 - 1 520
712 36̲3
3 280 + 513
253 537
4 000 - 2 500
9̲91 945
2 187 + 1 700
92 461
Write the next 3
numbers
3 660 - 3 060
52̲8 984
3 120 + 6 250
125; 135; 145
5 252 - 2 252
223 647̲
980; 960; 940
2 175 - 125
642 07̲1
200 + 400 + 600
28 279
Round off to
the nearest
1000
36; 48; 60
320 + 420 + 520
726 159
11; 16; 21
Write smallest
number using
Round off to the
nearest 1000
225 + 325 + 425
213 774
1 050; 1 025; 1 000
2; 6; 0; 8; 3; 1
371 642
610 + 2 350
307 261
535; 565; 595
3; 0; 9; 6; 4; 7
853 112
5 550 + 650
915 528
6 200; 6 000; 5 800
5; 7; 2; 8; 1; 9
240 649
1840 + 1015
104 509
108; 96; 84
3; 1; 6; 4; 0; 8
317 005
3 161 + 3 300
713 442
375; 400; 425
7; 3; 9; 1; 4; 2
614 567
951 + 1 050
635 483
625; 750; 875
5; 0; 6; 1; 7; 4
802 559
404 + 4 040
274 726
999; 899; 799
2; 5; 3; 8; 4; 6
387 615
2 615 + 300
5 145 + 4 541
600 + 600 + 600