6th grade GCF & LCM worksheets

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GCF and LCM worksheets give your child practice finding the greatest common factor of pairs up to 100 and the least common multiple of pairs up to 12, the skill 6th grade uses to factor expressions and add unlike fractions.

Free printable PDF worksheet, aligned to Common Core 6.NS.B.4.

Each print is a different sheet with its own answer key. You don't need to sign up.

The kind of problems you'll get

Read each direction. Complete every response.

  1. Find the greatest common factor. (3, 7)

    Answer: 1

  2. Find the least common multiple. (8, 8)

    Answer: 8

  3. Find the greatest common factor. (60, 44)

    Answer: 4

Every print pulls a fresh set of problems at this level, so a make-up test or a second sibling never gets the same sheet.

What's on a 6th grade sheet

Every version prints on US Letter or A4, with its answer key after the problems.

How to teach this

For GCF, list each number's factor pairs and circle the biggest factor they share. For LCM, count by each number aloud and stop at the first match: 4, 8, 12 meets 6, 12. Keep the two straight with a size check: the GCF divides in, the LCM holds both.

Watch for: GCF and LCM swap in kids' heads. The greatest common factor is never bigger than your numbers, and the least common multiple is never smaller. Kids assume multiplying the two numbers always gives the LCM. 4 × 6 is 24, but the least common multiple of 4 and 6 is 12.

Common questions about 6th grade GCF & LCM

How big are the numbers?
GCF pairs go up to 100 and LCM pairs stay at 12 or below, matching the 6th grade standard. Every print draws a new set of pairs.
Why do GCF and LCM share one worksheet?
Because telling them apart is most of the skill. Mixing the two question types on one sheet makes your child read the question before reaching for a method.

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Aligned to Common Core 6.NS.B.4. Reviewed by the One more sheet team. Content version 240, updated October 2026.

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