Printable Least Common Multiple Worksheets

Printable least common multiple worksheets for 4th and 5th grade, with an answer key on every sheet. The sets below cover 4 different skills, so you can start where your child actually is. Available as speed drills and word problems.

Targeted Practice by Skill

About Least Common Multiple

What this skill is

Least Common Multiple (LCM) is the smallest positive shared multiple of two or more numbers (e.g., LCM of 4 and 6 is 12).

When children learn it

LCM calculations are taught in 4th and 5th grade, supporting unlike denominator fraction addition.

Teaching Tips

  • List multiples of the larger number first, checking if the smaller number divides them.
  • Highlight the first matching shared multiple.

Common Mistakes

  • Multiplying two numbers together when a smaller common multiple exists (using 24 instead of 12 for 4 and 6).
  • Confusing LCM with GCF.