Year 6 Prime Factorisation (Factor Trees) Worksheet — Level 3 — Practice Set 4 — 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 4 — 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 154 as a product of prime factors in index form.
Answer: 2×7×11
- 154 = 2 × 77
- 77 = 7 × 11
- So 154 = 2 × 7 × 11 = 2 × 7 × 11
2.Which number has the prime factorisation 2 × 5 × 7?
Answer: 70
- 2 × 5 × 7 = 70
3.Use a factor tree to write 675 as a product of prime factors in index form.
Answer: 33×52
- 675 = 3 × 225
- 225 = 3 × 75
- 75 = 3 × 25
- 25 = 5 × 5
- So 675 = 3 × 3 × 3 × 5 × 5 = 33 × 52
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 110 as a product of prime factors in index form.
Answer: 2×5×11
- 110 = 2 × 55
- 55 = 5 × 11
- So 110 = 2 × 5 × 11 = 2 × 5 × 11
6.Which number has the prime factorisation 2 × 3 × 5 × 11?
Answer: 330
- 2 × 3 × 5 × 11 = 330
7.Use a factor tree to write 126 as a product of prime factors in index form.
Answer: 2×32×7
- 126 = 2 × 63
- 63 = 3 × 21
- 21 = 3 × 7
- So 126 = 2 × 3 × 3 × 7 = 2 × 32 × 7
8.Which number has the prime factorisation 2 × 7 × 11?
Answer: 154
- 2 × 7 × 11 = 154
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.