7th Grade Prime Factorization (Factor Trees) Worksheet — Level 3 — Practice Set 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 — 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 847 as a product of prime factors in index form.
Answer: 7×112
- 847 = 7 × 121
- 121 = 11 × 11
- So 847 = 7 × 11 × 11 = 7 × 112
2.Which number has the prime factorization 2 × 3 × 5 × 11?
Answer: 330
- 2 × 3 × 5 × 11 = 330
3.Use a factor tree to write 66 as a product of prime factors in index form.
Answer: 2×3×11
- 66 = 2 × 33
- 33 = 3 × 11
- So 66 = 2 × 3 × 11 = 2 × 3 × 11
4.Which number has the prime factorization 52 × 11?
Answer: 275
- 5 × 5 × 11 = 275
5.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
6.Which number has the prime factorization 2 × 32 × 11?
Answer: 198
- 2 × 3 × 3 × 11 = 198
7.Use a factor tree to write 605 as a product of prime factors in index form.
Answer: 5×112
- 605 = 5 × 121
- 121 = 11 × 11
- So 605 = 5 × 11 × 11 = 5 × 112
8.Which number has the prime factorization 3 × 52 × 11?
Answer: 825
- 3 × 5 × 5 × 11 = 825
Marking tips
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