Or, work with a partner (or the teacher) and play Fraction Domino War. Each person places a domino on their side of the whiteboard, and the student with the greatest fraction wins both dominos. The student with the most dominos at the end wins.
fraction basketball, let them roll a dice to see how many times each person will "shoot" then record shots made as a fraction. Person with the biggest fraction wins. LOVE this idea, except instead of shooting "basketballs" I wanna set up angry birds!