Year 5 Prime Factorisation (Factor Trees) Worksheet — Level 2 — Practice Set 3 — Answers
Answer sheet with worked solutions for the Year 5 factors, multiples & primes worksheet.
Success TutoringWorksheetsAnswer sheetYear 5 · Mathematics · Factors, Multiples & PrimesYear 5 Prime Factorisation (Factor Trees) Worksheet — Level 2 — Practice Set 3 — 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 252 as a product of prime factors.
Answer: 2×2×3×3×7
- 252 = 2 × 126
- 126 = 2 × 63
- 63 = 3 × 21
- 21 = 3 × 7
- So 252 = 2 × 2 × 3 × 3 × 7 = 22 × 32 × 7
2.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
3.Use a factor tree to write 140 as a product of prime factors.
Answer: 2×2×5×7
- 140 = 2 × 70
- 70 = 2 × 35
- 35 = 5 × 7
- So 140 = 2 × 2 × 5 × 7 = 22 × 5 × 7
4.Which number has the prime factorisation 2 × 3 × 52?
Answer: 150
- 2 × 3 × 5 × 5 = 150
5.Use a factor tree to write 210 as a product of prime factors.
Answer: 2×3×5×7
- 210 = 2 × 105
- 105 = 3 × 35
- 35 = 5 × 7
- So 210 = 2 × 3 × 5 × 7
6.Use a factor tree to write 189 as a product of prime factors.
Answer: 3×3×3×7
- 189 = 3 × 63
- 63 = 3 × 21
- 21 = 3 × 7
- So 189 = 3 × 3 × 3 × 7 = 33 × 7
7.Use a factor tree to write 56 as a product of prime factors.
Answer: 2×2×2×7
- 56 = 2 × 28
- 28 = 2 × 14
- 14 = 2 × 7
- So 56 = 2 × 2 × 2 × 7 = 23 × 7
8.Which number has the prime factorisation 3 × 72?
Answer: 147
- 3 × 7 × 7 = 147
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.