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 330 as a product of prime factors in index form.
Answer: 2×3×5×11
- 330 = 2 × 165
- 165 = 3 × 55
- 55 = 5 × 11
- So 330 = 2 × 3 × 5 × 11 = 2 × 3 × 5 × 11
2.Which number has the prime factorisation 2 × 112?
Answer: 242
- 2 × 11 × 11 = 242
3.Use a factor tree to write 105 as a product of prime factors in index form.
Answer: 3×5×7
- 105 = 3 × 35
- 35 = 5 × 7
- So 105 = 3 × 5 × 7 = 3 × 5 × 7
4.Which number has the prime factorisation 2 × 3 × 5 × 11?
Answer: 330
- 2 × 3 × 5 × 11 = 330
5.Use a factor tree to write 924 as a product of prime factors in index form.
Answer: 22×3×7×11
- 924 = 2 × 462
- 462 = 2 × 231
- 231 = 3 × 77
- 77 = 7 × 11
- So 924 = 2 × 2 × 3 × 7 × 11 = 22 × 3 × 7 × 11
6.Which number has the prime factorisation 2 × 7 × 11?
Answer: 154
- 2 × 7 × 11 = 154
7.Use a factor tree to write 147 as a product of prime factors in index form.
Answer: 3×72
- 147 = 3 × 49
- 49 = 7 × 7
- So 147 = 3 × 7 × 7 = 3 × 72
8.Which number has the prime factorisation 2 × 52 × 7?
Answer: 350
- 2 × 5 × 5 × 7 = 350
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.