← Back to lesson

Readnary · Original practice

Number types and prime factors

Practice worksheet

AI-assisted practice — not independently academically reviewed. Answers may contain errors; check important results against your course materials.

Use your browser’s Print command to print or save as PDF. Choose one answer and show your working.

Name: __________________________ Date: __________________

1. Using the convention that natural numbers begin at 1, which number is a natural number?

  1. −4
  2. 0
  3. 3
  4. 1/2

2. Which number is an integer but not a natural number under this pack's convention?

  1. −7
  2. 2/3
  3. √2
  4. 5.4

3. Which statement about 0 is correct?

  1. It is positive and rational.
  2. It is negative and integer.
  3. It is rational but not positive.
  4. It is irrational and real.

4. Which number is rational?

  1. √3
  2. π
  3. 0.125
  4. √7

5. Which number is irrational?

  1. √49
  2. −3/8
  3. 0.6
  4. √10

6. Which description includes both rational and irrational numbers?

  1. Natural numbers
  2. Integers
  3. Prime numbers
  4. Real numbers

7. Which number is prime?

  1. 1
  2. 21
  3. 29
  4. 51

8. Which number is a square number?

  1. 18
  2. 36
  3. 54
  4. 72

9. Which number is a cube number?

  1. −27
  2. −18
  3. 12
  4. 48

10. Which number is a factor of 84?

  1. 5
  2. 7
  3. 9
  4. 11

11. Which number is a common multiple of 6 and 8?

  1. 18
  2. 24
  3. 32
  4. 42

12. What is the prime factorisation of 84?

  1. 2 × 3 × 14
  2. 2² × 3 × 7
  3. 2 × 3² × 7
  4. 4 × 3 × 7

13. What is the HCF of 18 and 30?

  1. 3
  2. 6
  3. 9
  4. 90

14. What is the LCM of 12 and 15?

  1. 3
  2. 30
  3. 60
  4. 180

15. What is the reciprocal of −3/5?

  1. 3/5
  2. −5/3
  3. 5/3
  4. −3/5

16. What is the reciprocal of 0?

  1. 0
  2. 1
  3. −1
  4. It is undefined.

17. What is the most specific classification of −3/5 among these choices?

  1. Natural
  2. Integer
  3. Rational
  4. Irrational

18. Which figure represents three billion, five million and forty-two?

  1. 3 500 000 042
  2. 3 050 000 042
  3. 3 005 000 042
  4. 3 000 005 042

19. A number has prime factorisation 2³ × 3² × 5. Which value is a factor of the number?

  1. 2⁴ × 3
  2. 2² × 3 × 5
  3. 2 × 3³
  4. 3² × 5²

20. A floor measuring 168 cm by 252 cm is covered by the largest possible identical square tiles, with no cutting. What is the side length of each tile?

  1. 28 cm
  2. 42 cm
  3. 84 cm
  4. 126 cm

21. Three signals flash every 18 seconds, 24 seconds and 30 seconds. They flash together now. After how many seconds will they next flash together?

  1. 72
  2. 120
  3. 180
  4. 360

22. What is the HCF of 84 and 126?

  1. 14
  2. 21
  3. 42
  4. 252

23. What is the LCM of 72 and 120?

  1. 24
  2. 120
  3. 240
  4. 360

24. What is the smallest positive integer that is divisible by 8, 12 and 18?

  1. 36
  2. 48
  3. 72
  4. 144

Published revision 3 · 2026-09-08 · Not an official exam paper.