This book is called Miss Daisy is Crazy which is one of the series of My Weird School. 

This book is about a boy named A.J. who doesn’t like school. His new teacher, Miss Daisy, surprises everyone because she says she doesn’t know how to read, write, or do math. The kids think it’s funny and crazy. A.J. and his classmates try to teach her things, and they even come up with silly ideas like turning the school into a video game arcade. In the end, they realize Miss Daisy is smarter than she seems, and she actually teaches them in her own funny way.