The Search for the Missing Bones (A magic school bus science chapter book) by Eva Moore

The Skeleton Scare takes readers through the Hugh Mann Costume Company, where they'll learn about a different bone in each room. As Ms. Frizzle and her class work their way through the factory, they keep seeing a strange skeleton. Yikes! Is it following them? Maybe, but it doesn't stop the kids from learning all about skeletons: why we need them, what different bones are for, what makes bones grow, how bones get fixed after they've been broken, and lots of other facts about our skeletons.