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 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
2.Which number has the prime factorisation 2 × 7 × 11?
Answer: 154
- 2 × 7 × 11 = 154
3.Use a factor tree to write 180 as a product of prime factors in index form.
Answer: 22×32×5
- 180 = 2 × 90
- 90 = 2 × 45
- 45 = 3 × 15
- 15 = 3 × 5
- So 180 = 2 × 2 × 3 × 3 × 5 = 22 × 32 × 5
4.Which number has the prime factorisation 2 × 52 × 7?
Answer: 350
- 2 × 5 × 5 × 7 = 350
5.Use a factor tree to write 315 as a product of prime factors in index form.
Answer: 32×5×7
- 315 = 3 × 105
- 105 = 3 × 35
- 35 = 5 × 7
- So 315 = 3 × 3 × 5 × 7 = 32 × 5 × 7
6.Which number has the prime factorisation 2 × 3 × 7 × 11?
Answer: 462
- 2 × 3 × 7 × 11 = 462
7.Use a factor tree to write 150 as a product of prime factors in index form.
Answer: 2×3×52
- 150 = 2 × 75
- 75 = 3 × 25
- 25 = 5 × 5
- So 150 = 2 × 3 × 5 × 5 = 2 × 3 × 52
8.Which number has the prime factorisation 32 × 7 × 11?
Answer: 693
- 3 × 3 × 7 × 11 = 693
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
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