Dan Gutman 
My Weirder-est School #10: Mr. Ott Is a Crackpot! 

With more than 30 million books sold, the My Weird School series really gets kids reading! This tenth book in the My Weirder-est School arc knocks it out of the park as A.J. and his friends learn how to play softball. Batter up! A.J.s class is going head-to-head against Dirk School in a charity softball game. The losing team must clean one of the toilets in the winning school with a toothbrush!Retired baseball pro Mr. Ott is here to lead Ella Mentry School to victory. But will his weird coaching tactics be a home run, or a swing and a miss?Perfect for reluctant readers and all kids hungry for funny school stories, Dan Gutmans hugely popular My Weird School chapter book series has something for everyone. Dont miss the hilarious adventures of A.J. and the gang!