Year 6 Prime Factorisation (Factor Trees) Worksheet — Level 3 — Practice Set 2 — Answers
Answer sheet with worked solutions for the Year 6 factors, multiples & primes worksheet.
Success TutoringWorksheetsAnswer sheetYear 6 · Mathematics · Factors, Multiples & PrimesYear 6 Prime Factorisation (Factor Trees) Worksheet — Level 3 — Practice Set 2 — Answers
Keep splitting each number into two factors until every branch ends in a prime. Write repeated factors with an index, e.g. 2 × 2 × 2 = 23.
1.Use a factor tree to write 66 as a product of prime factors in index form.
Answer: 2×3×11
- 66 = 2 × 33
- 33 = 3 × 11
- So 66 = 2 × 3 × 11 = 2 × 3 × 11
2.Which number has the prime factorisation 2 × 52 × 7?
Answer: 350
- 2 × 5 × 5 × 7 = 350
3.Use a factor tree to write 550 as a product of prime factors in index form.
Answer: 2×52×11
- 550 = 2 × 275
- 275 = 5 × 55
- 55 = 5 × 11
- So 550 = 2 × 5 × 5 × 11 = 2 × 52 × 11
4.Which number has the prime factorisation 3 × 5 × 7?
Answer: 105
- 3 × 5 × 7 = 105
5.Use a factor tree to write 539 as a product of prime factors in index form.
Answer: 72×11
- 539 = 7 × 77
- 77 = 7 × 11
- So 539 = 7 × 7 × 11 = 72 × 11
6.Which number has the prime factorisation 2 × 5 × 72?
Answer: 490
- 2 × 5 × 7 × 7 = 490
7.Use a factor tree to write 525 as a product of prime factors in index form.
Answer: 3×52×7
- 525 = 3 × 175
- 175 = 5 × 35
- 35 = 5 × 7
- So 525 = 3 × 5 × 5 × 7 = 3 × 52 × 7
8.Which number has the prime factorisation 2 × 3 × 112?
Answer: 726
- 2 × 3 × 11 × 11 = 726
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.