See the difference this hands-on math manipulative can make! Children learn addition by watching the process play out before their eyes. Simply put the magnetic funnel, cups and tray on any magnetic-receptive surface, like a whiteboard. Then, send the balls through the cups to demonstrate simple addition concepts. It's an ingenious way to keep your students engaged. Set includes 2 cups, funnel, 20 balls (10 green, 10 purple), and tray. Tray measures 11"L.