A New Toy That Teaches

Tiger Electronics' handheld game Lights Out is something that even teachers might want you to bring to class. At the University of Wyoming, math professor Leslie Shader uses the game to illustrate principles of matrix theory. The internal logic of Lights Out is based on algorithms that create 1,000 patterns of lit and unlit buttons. When you press one of 25 buttons, it and adjacent buttons turn off or on; the object is to turn off all the lights in the fewest moves. Shader says dryly: "It's just a lot of fun to play."