Help your students learn essential math skills in a flash with this durable and innovative classroom supply! They'll quickly and easily learn number fact fluency. Kids will comprehend adding, subtracting and multiplying in an exciting way with this handheld device. Use the 60-second timer, or let them work at a slower pace with the untimed mode. Plastic. 5 1/2" Requires 3 "AAA" batteries, not included.