sound cups 20 small plastic cups (not see through) plastic wrap 20 rubberbands 10 sound materials (rice, and, peppercorns, nuts, buttons coins bells pins seeds ect) Method place different materials in each cup. Make ten double sets. Cover with wrap and secure with rubber band. Start with two sets ( 2 rice and 2 sand). Shake each cup and listen carefully. Then close your eyes and try to pair each set by sound alone. .