It's never easy for Sammy Hayes-Rodriguez to fit in, so he's dreading the day when his genius mom insists he bring her newest invention to school: a robot he calls E--for ''Error''. E not only thinks he's Sammy's brother. . . he's actually even nerdier than Sammy. Will E be Sammy's one-way ticket to Loserville? Or will he prove to the world that it's cool to be square?