A visual way to teach addition! Just stick the magnetic cups, funnel, and tray to any whiteboard for clear and simple addition demonstrations. Drop the balls into the cups, tilt them over so they fall into the addition funnel and through to the numbered tray, and then count them up! Includes 2 cups, funnel, 20 balls (10 green, 10 purple), number line, equals sign, and tray. Tray measures 11L.