Why was Mr. Keesing annoyed with Anne? What did he ask her to do?

Answer – Anne Frank was a chatterbox. She talked every time in the class. That was why her math teacher, Mr. Keesing was annoyed with her. He first assigned an essay on "A Chatterbox", then "An Incorrigible Chatterbox", and finally "Quack, Quack, Quack, Said Mistress Chatterbox".