Year 6 Prime Factorisation (Factor Trees) Worksheet — Level 2 — Practice Set 2 — Answers
Answer sheet with worked solutions for the Year 6 factors, multiples & primes worksheet.
Year 6 Prime Factorisation (Factor Trees) Worksheet — Level 2 — Practice Set 2 — Answers
Keep splitting each number into two factors until every branch ends in a prime. Write the primes from smallest to largest.
1.Use a factor tree to write 300 as a product of prime factors.
Answer: 2×2×3×5×5
- 300 = 2 × 150
- 150 = 2 × 75
- 75 = 3 × 25
- 25 = 5 × 5
- So 300 = 2 × 2 × 3 × 5 × 5 = 22 × 3 × 52
2.Use a factor tree to write 126 as a product of prime factors.
Answer: 2×3×3×7
- 126 = 2 × 63
- 63 = 3 × 21
- 21 = 3 × 7
- So 126 = 2 × 3 × 3 × 7 = 2 × 32 × 7
3.Use a factor tree to write 60 as a product of prime factors.
Answer: 2×2×3×5
- 60 = 2 × 30
- 30 = 2 × 15
- 15 = 3 × 5
- So 60 = 2 × 2 × 3 × 5 = 22 × 3 × 5
4.Which number has the prime factorisation 2 × 3 × 5 × 7?
Answer: 210
- 2 × 3 × 5 × 7 = 210
5.Use a factor tree to write 70 as a product of prime factors.
Answer: 2×5×7
- 70 = 2 × 35
- 35 = 5 × 7
- So 70 = 2 × 5 × 7
6.Use a factor tree to write 147 as a product of prime factors.
Answer: 3×7×7
- 147 = 3 × 49
- 49 = 7 × 7
- So 147 = 3 × 7 × 7 = 3 × 72
7.Use a factor tree to write 180 as a product of prime factors.
Answer: 2×2×3×3×5
- 180 = 2 × 90
- 90 = 2 × 45
- 45 = 3 × 15
- 15 = 3 × 5
- So 180 = 2 × 2 × 3 × 3 × 5 = 22 × 32 × 5
8.Which number has the prime factorisation 2 × 33?
Answer: 54
- 2 × 3 × 3 × 3 = 54
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.