Topic B: Divisibility

Divisibility is when two numbers can be divided without a remainder.

For example, 18 is divisible by 3 because 18 ÷ 3 = 6.

18 is not divisible by 5 because 18 ÷ 5 = 3 with a remainder of 3.

Divisibility by 2

A number is divisible by 2 if it ends in 0, 2, 4, 6 or 8.

Example A

438, 540, 256, 12, and 154 are all divisible by 2 because each number ends in a 0, 2, 4, 6, or 8.

Example B

351, 945, 849, 347, and 193 are not divisible by 2 because each number does not end in a 0, 2, 4, 6 or 8.

Exercise 1

Circle the numbers that are divisible by 2. Check your work using the answer key at the end of the exercise.

  1. 22
  2. 35
  3. 17
  4. 10
  5. 274
  6. 345
  7. 639
  8. 456
  9. 2437
  10. 7548
  11. 6754
  12. 5543

Divisibility by 3

A number is divisible by 3 if the sum (total) of the digits is divisible by 3.

Example C

63

6 + 3 = 9

9 is divisible by three, so 63 is divisible by three.

Example D

148

1 + 4 + 8 = 13

13 is not divisible by three, so 148 is not divisible by 3.

Example E

5892

5 + 8 + 9 + 2 = 24

Add again: 2 + 4 = 6

6 is divisible by 3, so 5892 is divisible by 3.

Exercise 2

Circle the numbers that are divisible by 3. Check your work using the answer key at the end of the exercise.

  1. 27
  2. 35
  3. 81
  4. 94
  5. 274
  6. 581
  7. 564
  8. 316
  9. 3175
  10. 1458
  11. 1890
  12. 3934

Divisibility by 5

A number is divisible by 5 if the number ends in 0 or 5.

Example F

290 is divisible by 5 because it ends in 0.

Example G

132 is not divisible by 5 because it does not end in 0 or 5.

Exercise 3

Circle the numbers that are divisible by 5. Check your work using the answer key at the end of the exercise.

  1. 45
  2. 84
  3. 72
  4. 90
  5. 800
  6. 753
  7. 672
  8. 355
  9. 6009
  10. 6375
  11. 7020
  12. 1704

Answers to Exercise 1
The following numbers are divisible by 2: a, d, e, h, j, k.

Answers to Exercise 2

The following numbers are divisible by 3: a, c, g, j, k.

Answers to Exercise 3

The following numbers are divisible by 5: a, d, e, h, j, k.

Exercise 4

For each number, identify if it is divisible by 2, 3, and 5. Check your work using the answer key at the end of the exercise.

Number Divisible by 2 Divisible by 3 Divisible by 5
474 Yes Yes No
615
412
865
300
831
525
350
710
429
906
634
430
275

Answers to Exercise 4

Number Divisible by 2 Divisible by 3 Divisible by 5
474 Yes Yes No
615 No Yes Yes
412 Yes No No
865 No No Yes
300 Yes Yes Yes
831 No Yes No
525 No Yes Yes
350 Yes No Yes
710 Yes No Yes
429 No Yes No
906 Yes Yes No
634 Yes No No
430 Yes No Yes
275 No No Yes

Exercise 5

For each number, identify if it is divisible by 2, 3, and 5. Check your work using the answer key at the end of the exercise.

Number Divisible by 2 Divisible by 3 Divisible by 5
3585
7548
5890
6318
3905
5280
1760
8007
6752
7375
5523
2625
8956
9150

Answers to Exercise 5

Number Divisible by 2 Divisible by 3 Divisible by 5
3585 No Yes Yes
7548 Yes Yes No
5890 Yes No Yes
6318 Yes Yes No
3905 No No Yes
5280 Yes Yes Yes
1760 Yes No Yes
8007 No Yes No
6752 Yes No No
7375 No No Yes
5523 No Yes No
2625 No Yes Yes
8956 Yes No No
9150 Yes Yes Yes

Divisibility by 9

A number is divisible by 9 if the sum (total) of the digits is divisible by 9.

Example H

 

135

1 + 3 + 5 = 9

9 is divisible by 9, so 135 is divisible by 9.

Example I

7578

7 + 5 + 7 + 8 = 27

27 is divisible by 9, so 7578 is divisible by 9.

Example J

57896

5 + 7 + 8 + 9 + 6 = 35

35 is not divisible by 9, so 57896 is not divisible by 9.

Exercise 6

Circle the numbers that are divisible by 9. Check your work using the answer key at the end of the exercise.

  1. 538
  2. 783
  3. 954
  4. 762
  5. 6213
  6. 5742
  7. 7083
  8. 5738
  9. 34937
  10. 39402
  11. 74124
  12. 45683

Answers to Exercise 6

The following numbers are divisible by 9: b, c, f, g, j, k

Exercise 7

For each number, identify if it is divisible by 2, 3, 5, and 9. Check your work using the answer key at the end of the exercise.

Number Divisible by 2 Divisible by 3 Divisible by 5 Divisible by 9
453
320
216
726
712
425
630
375
990

Answers to Exercise 7

Number Divisible by 2 Divisible by 3 Divisible by 5 Divisible by 9
453 No Yes No No
320 Yes No Yes No
216 Yes Yes No Yes
726 Yes Yes No No
712 Yes No No No
425 No No Yes No
630 Yes Yes Yes Yes
375 No Yes Yes No
990 Yes Yes Yes Yes
Exercise 8

For each number, identify if it is divisible by 2, 3, 5, and 9.

Number Divisible by 2 Divisible by 3 Divisible by 5 Divisible by 9
837
360
648
981
465
1002
3520
6435
8022

Answers to Exercise 8

Number Divisible by 2 Divisible by 3 Divisible by 5 Divisible by 9
837 No Yes No Yes
360 Yes Yes Yes Yes
648 Yes Yes No Yes
981 No Yes No Yes
465 No Yes Yes No
1002 Yes Yes No No
3520 Yes No Yes No
6435 No Yes Yes Yes
8022 Yes Yes No No
Exercise 9

For each number, identify if it is divisible by 2, 3, 5, and 9.

Number Divisible by 2 Divisible by 3 Divisible by 5 Divisible by 9
1200
7164
3681
8205
2745
4320
7350
4000
1368

Answers to Exercise 9

Number Divisible by 2 Divisible by3 Divisible by 5 Divisible by 9
1200 Yes Yes Yes No
7164 Yes Yes No Yes
3681 No Yes No Yes
8205 No Yes Yes No
2745 No Yes Yes Yes
4320 Yes Yes Yes Yes
7350 Yes Yes Yes No
4000 Yes No Yes No
1368 Yes Yes No Yes

Topic B: Self-Test

Mark /12          Aim 9/12

A. From the list of numbers, write the numbers that are divisible by the specified number.

48            925             1467             2645             5534             7512            31183            52361

 

  1. Which numbers are divisible by 2?
  2. Which numbers are divisible by 3?
  3. Which numbers are divisible by 5?
  4. Which numbers are divisible by 9?

B. For each number, identify if it is divisible by 2, 3, 5, and 9.

Number Divisible by 2 Divisible by 3 Divisible by 5 Divisible by 9
1200
7164
3681
8205
2745

Answers to Topic B Self Test

A. From the list of numbers, write the numbers that are divisible by the specified number.

  1. 48, 7512, 5534
  2. 48, 1467, 7512
  3. 925, 2645
  4. 1467

B. For each number, identify if it is divisible by 2, 3, 5, and 9.

Number Divisible by 2 Divisible by 3 Divisible by 5 Divisible by 9
1200 Yes Yes Yes No
7164 Yes Yes No Yes
3681 No Yes No Yes
8205 No Yes Yes No
2745 No Yes Yes Yes

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Fundamentals of Mathematics 3 Copyright © 2023 by Wendy Tagami and Liz Girard is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.