Factors & Primes
Find factors, multiples, primes, and use LCM and HCF to solve problems.
What your child learns
- Factors divide a number exactly; multiples are in its times table
- A prime has exactly two factors: 1 and itself
- Use LCM and HCF in real-life problems
Example
Factors of 12: 1, 2, 3, 4, 6, 12. 7 is prime.
Practice questions
A taste of the questions in BloomTracks – the app makes fresh ones every time and adjusts the level as your child answers.
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Question 1 · Level 1
Which number is a multiple of 7?
- 72
- 70
- 69
- 73
Show the answer
Answer: 70
10 × 7 = 70, so 70 is a multiple of 7.
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Question 2 · Level 3
Which number is prime?
- 91
- 61
- 55
- 27
Show the answer
Answer: 61
61 can only be divided by 1 and 61. The others can be split into smaller factors.
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Question 3 · Level 5
What is the prime factorisation of 63?
- 3 × 3 × 8
- 3 × 3 × 7
- 3 × 21
- 9 × 7
Show the answer
Answer: 3 × 3 × 7
63 = 3 × 3 × 7 (all prime).
Try it at home
Find all the ways to arrange 12 or 24 objects in equal rows.
Key takeaway
Find factors in pairs: 1 × 12, 2 × 6, 3 × 4.
Practise factors & primes with Bloomie
Bloomie reads every question aloud, listens to spoken answers and adapts the difficulty one question at a time.