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 693 as a product of prime factors in index form.
Answer: 32×7×11
- 693 = 3 × 231
- 231 = 3 × 77
- 77 = 7 × 11
- So 693 = 3 × 3 × 7 × 11 = 32 × 7 × 11
2.Which number has the prime factorisation 32 × 72?
Answer: 441
- 3 × 3 × 7 × 7 = 441
3.Use a factor tree to write 567 as a product of prime factors in index form.
Answer: 34×7
- 567 = 3 × 189
- 189 = 3 × 63
- 63 = 3 × 21
- 21 = 3 × 7
- So 567 = 3 × 3 × 3 × 3 × 7 = 34 × 7
4.Which number has the prime factorisation 22 × 3 × 11?
Answer: 132
- 2 × 2 × 3 × 11 = 132
5.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
6.Which number has the prime factorisation 5 × 7 × 11?
Answer: 385
- 5 × 7 × 11 = 385
7.Use a factor tree to write 90 as a product of prime factors in index form.
Answer: 2×32×5
- 90 = 2 × 45
- 45 = 3 × 15
- 15 = 3 × 5
- So 90 = 2 × 3 × 3 × 5 = 2 × 32 × 5
8.Which number has the prime factorisation 3 × 52 × 7?
Answer: 525
- 3 × 5 × 5 × 7 = 525
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.