Napoli, Donna Jo. The Wishing Club: A Story About Fractions. Illus. Anna Currey. New York: Henry Holt & Company, 2007. (Grades 3-6)
Eight-year-old Sally, her twin sister, and her two brothers form a wishing club after Petey and Joey both make wishes on a comet, only to get a fraction of the item they wished for: Petey wishes for a dollar, but gets a quarter and Joey wishes for a cookie and gets a half of a cookie. The siblings quickly realize that though this wishing business is warped, it does have its benefits. Something or someone seems to be using their ages to reward them with a fraction of the item they requested. SO they decide to pool their wishes and focus on one thing: a pet pig. Luckily each child doesn’t end up with a ham or an ear. Instead, they get a cute piglet.
Take a look at Math Books to see more math oriented books for grades K-8.