Someday Angeline — Louis Sachar

Nobody understands why Angeline is so smart. She could read the first time she picked up a book, she can play the piano without ever having had a lesson, and she even knows what the weather is going to be. But being smart is causing Angeline nothing but trouble. The mean kids in school call her a freak, her teacher finds her troublesome, and even her own father doesn't know what to do with an eight-year-old girl who seems to be a genius. Angeline doesn't want to be either a genius or a freak. She just wants the chance to be herself and be happy. But it's only when she makes friends with a boy the kids call "Goon" and a teacher they call "Mr. Bone" that Angeline gets that chance.