Tape 3 balloons to the board, etc., and give students time to count balloons. Then without warning, pop one balloon. The younger students are thrilled about the action. Teacher then asks, "How many balloons left?" Students will enjoy discussing the popping of one balloon. Ask someone to tell you what subtraction number sentence could be written to show what just happened. Continue this activity (mostly for the fun of it) to teach the concept of subtraction. Use appropriate level number sentences.