Matilda by Roald Dahl.

Matilda Wormwood is only five years old, but she is a genius. Unfortunately, her parents don’t even notice. Worse, her horrible headmistress Miss Trunchbull is a bully who makes life difficult for Matilda’s teacher, Miss Honey, and her friends. But what Miss Trunchbull doesn’t know is that Matilda has a trick or two up her sleeve.