Divide students into pairs, and give each pair of students a deck of cards. Have students divide the deck in half so that each student has 26 cards. Then have them each turn over their top card and place it on the table. The first student to find the lowest common multiple (LCM) of the two numbers gets to keep the cards. The student who has all of the cards at the end of the game wins! You can make this game into a tournament if you’d like.
You can play this game to review greatest common factors (GCF) as well. To do this, however, you’ll have to make your own cards, photocopy them, and have them pairs of students cut them out before playing. Make sure to choose many higher numbers that have multiple factors, such as 12, 32, 40, or 45. Remind students that sometimes the greatest common factor will be “one”!