Year 6 Prime Factorisation (Factor Trees) Worksheet — Level 3 — Practice Set 3 — 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 3 — 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 363 as a product of prime factors in index form.
Answer: 3×112
- 363 = 3 × 121
- 121 = 11 × 11
- So 363 = 3 × 11 × 11 = 3 × 112
2.Which number has the prime factorisation 2 × 52 × 7?
Answer: 350
- 2 × 5 × 5 × 7 = 350
3.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
4.Which number has the prime factorisation 25 × 7?
Answer: 224
- 2 × 2 × 2 × 2 × 2 × 7 = 224
5.Use a factor tree to write 350 as a product of prime factors in index form.
Answer: 2×52×7
- 350 = 2 × 175
- 175 = 5 × 35
- 35 = 5 × 7
- So 350 = 2 × 5 × 5 × 7 = 2 × 52 × 7
6.Which number has the prime factorisation 2 × 3 × 112?
Answer: 726
- 2 × 3 × 11 × 11 = 726
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 22 × 3 × 5 × 7?
Answer: 420
- 2 × 2 × 3 × 5 × 7 = 420
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.