Does "Math Wiz" have to equal "Sports Dud"?

Marty Malone thinks no problem is too complicated for him. Then he starts third grade--and learns that being a math wiz won't stop him from getting picked last in gym class. Kids like tom Ballan are so much better at sports that Marty will never be able to catch up. Trying harder doesn't work. Trying to get out of gym doesn't work. But what if Marty makes a friend in class? And what if that friend is a math wiz, too?