Greatest common factor (GCF) and least common multiple (LCM)
Online practice for grades 5-8

On this page, you can practice finding the greatest common factor (GCF) and the least common multiple (LCM) of two, three, or four numbers.

You can choose timed or untimed practice, the number of practice problems, and the quantity of numbers. There's also an option for "easy mode", which uses smaller numbers than the regular mode.


Screenshot of someone doing a round

Practice for a set time: min

Correct: 0   Wrong: 0

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