阅读短文,回答问题
Tom is a lovely boy. He likes playing football very much. He often comes back between 4p. m and 5p. m. Today he comes back late. His mother says "you come back home late today, Tom".
"Yes, we have a new teacher, He is a math teacher," Tom answers.
"How is he?" His mother asks.
"I don't know, I think I can't believe him. "
"How is that" his mother says.
"One moment he says two and three is five and the next moment he says one and four is five. " Tom answers.