Greatest Common Factor (GCF) &
Least Common Multiple (LCM)

Note to coach: There are a lot of these type problems in the WSMC Olympiad problem sets, especially those that use the LCM-GCF equation for both finding the GCF and the LCM. We recommend you deliver this lesson if you are taking your students to the Olympiad. The 2008 Olympiad 5th grade number sense quiz had 2 of these types of problems!