My Robot Buddy — Alfred Slote

On Jack's tenth birthday, his parents give him just what he wants--a robot. The robot's name is Danny One, and he looks just like Jack, except for his stiff-in-the-knees robot walk. He can do everything Jack can do, from fourth-grade math to fishing, and much more besides. It's a good thing too, because Jack needs all the help he can get in order to foil an evil robotnapper!