These sites can help children understand multiples and factors and the difference between them. They also contain lessons on Least Common Multiple (LCM) and Greatest Common Factor (GCF). Includes interactive games, online exercises, in-class activities, and online factor generators.
In this online game you can find factors and multiples along with powers, prime and triangular numbers. Click on the "Key Idea" link at the top to learn what these numbers are. Select a difficulty level and start the game. NOTE: The "Talk" link leads to message boards.
This page contains extended information about factors. Select the "Now You Try" link for online exercises. At the very bottom of the page find a link to the "Least Common Multiple (LCM), Greatest Common Factor (GCF)."