Mixed review of GCF and LCM

5th Grade Math practice: Should you use GCF or LCM to find when 3-minute and 5-minute games start together again. Part of factors and multiples (Factors and multiples).

~8 min

Decide whether the problem is about common grouping or repeating cycles.

Choosing GCF or LCM

Choosing the Right Tool
  • GCF: Splitting items into equal groups
  • LCM: Finding when cycles meet again

Choose GCF when splitting items into the largest equal groups. Choose LCM when finding the next time repeating cycles meet.

💡 Think 'Group = GCF' and 'Cycle = LCM'.