7th Grade Prime Factorization (Factor Trees) Worksheet — Level 3 — Answers
Answer sheet with worked solutions for the 7th Grade factors, multiples & primes worksheet.
Success TutoringWorksheetsAnswer sheet7th Grade · Mathematics · Factors, Multiples & Primes7th Grade Prime Factorization (Factor Trees) Worksheet — Level 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 165 as a product of prime factors in index form.
Answer: 3×5×11
- 165 = 3 × 55
- 55 = 5 × 11
- So 165 = 3 × 5 × 11 = 3 × 5 × 11
2.Which number has the prime factorization 3 × 7 × 11?
Answer: 231
- 3 × 7 × 11 = 231
3.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
4.Which number has the prime factorization 2 × 3 × 11?
Answer: 66
- 2 × 3 × 11 = 66
5.Use a factor tree to write 495 as a product of prime factors in index form.
Answer: 32×5×11
- 495 = 3 × 165
- 165 = 3 × 55
- 55 = 5 × 11
- So 495 = 3 × 3 × 5 × 11 = 32 × 5 × 11
6.Which number has the prime factorization 23 × 3 × 5 × 7?
Answer: 840
- 2 × 2 × 2 × 3 × 5 × 7 = 840
7.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
8.Which number has the prime factorization 2 × 52 × 11?
Answer: 550
- 2 × 5 × 5 × 11 = 550
Marking tips
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