Factors, Multiples & Prime Factorisation — Worksheet & Memo

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Grade 8 · Whole Numbers

Factors, Multiples & Prime Factorisation

MEMORANDUM

Name:

Class:

Date:

Mark

/ 14

Answer all questions. Show all your working — marks are awarded for method as well as the final answer. Teacher copy: accept any correct equivalent method.

1
List all the factors of 36.
(2)
1, 2, 3, 4, 6, 9, 12, 18, 36✓✓ (2)
2
List all the factors of 40.
(2)
1, 2, 4, 5, 8, 10, 20, 40✓✓ (2)
3
Write down the first five multiples of 8.
(2)
8, 16, 24, 32, 40✓✓ (2)
4
Is 51 a prime number? Give a reason.
(2)
No — 51 = 3 × 17, so it has factors besides 1 and itself.✓✓ (2)
5
Write down all the prime numbers between 20 and 30.
(2)
23 and 29✓✓ (2)
6
Write 90 as a product of its prime factors.
(2)
90 = 2 × 3² × 5 (= 2 × 3 × 3 × 5)✓✓ (2)
7
Write 84 as a product of its prime factors.
(2)
84 = 2² × 3 × 7 (= 2 × 2 × 3 × 7)✓✓ (2)

TOTAL: 14 marks