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Free GCF, LCM & Prime Factorization Worksheets (Grade 6) — with Answer Keys

Print a GCF and LCM worksheet for grade 6 below — greatest common factor, least common multiple, and prime factorization — with a complete answer key. Generate a fresh sheet anytime, no signup.

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GCF, LCM & Prime Factorization — Grade 6

Greatest common factor

1.Find the least common multiple of 17 and 22.

2.Find the least common multiple of 18 and 22.

3.Find the greatest common factor of 14 and 13.

4.Find the greatest common factor of 14 and 20.

Least common multiple

5.Two positive integers have greatest common divisor 2 and product 504. What is their least common multiple?

6.What is the least common multiple (LCM) of 16 and 28?

7.What is the least common multiple (LCM) of 18 and 15?

8.Two positive integers have greatest common divisor 1 and product 650. What is their least common multiple?

Greatest common divisor

9.What is the greatest common divisor (GCD) of 15 and 17?

10.What is the greatest common divisor (GCD) of 22 and 25?

11.What is the greatest common divisor (GCD) of 20 and 27?

12.What is the greatest common divisor (GCD) of 14 and 19?

Prime factorization

13.How many prime factors (counted with repeats) does 30 have? For example 12 = 2 × 2 × 3 has three.

14.How many prime factors (counted with repeats) does 50 have? For example 12 = 2 × 2 × 3 has three.

15.How many prime factors (counted with repeats) does 60 have?

16.How many prime factors (counted with repeats) does 54 have?

Answer Key

1.374

2.198

3.1

4.2

5.252

6.112

7.90

8.650

9.1

10.1

11.1

12.1

13.3

14.3

15.4

16.4

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Are these GCF and LCM worksheets free?
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Every worksheet has a full answer key at the bottom of the page.

What grades are these GCF and LCM worksheets for?
They are designed for Grade 6.

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