Year 5 Prime Factorisation (Factor Trees) Worksheet — Level 2 — Practice Set 4 — 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 4 — 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 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
2.Use a factor tree to write 50 as a product of prime factors.
Answer: 2×5×5
- 50 = 2 × 25
- 25 = 5 × 5
- So 50 = 2 × 5 × 5 = 2 × 52
3.Use a factor tree to write 294 as a product of prime factors.
Answer: 2×3×7×7
- 294 = 2 × 147
- 147 = 3 × 49
- 49 = 7 × 7
- So 294 = 2 × 3 × 7 × 7 = 2 × 3 × 72
4.Which number has the prime factorisation 33 × 7?
Answer: 189
- 3 × 3 × 3 × 7 = 189
5.Use a factor tree to write 63 as a product of prime factors.
Answer: 3×3×7
- 63 = 3 × 21
- 21 = 3 × 7
- So 63 = 3 × 3 × 7 = 32 × 7
6.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
7.Use a factor tree to write 75 as a product of prime factors.
Answer: 3×5×5
- 75 = 3 × 25
- 25 = 5 × 5
- So 75 = 3 × 5 × 5 = 3 × 52
8.Which number has the prime factorisation 22 × 3 × 5?
Answer: 60
- 2 × 2 × 3 × 5 = 60
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.