Bob is a lovely schoolboy. He likes playing football very much. He often plays football with his classmates after school, but he never goes home too late. He usually gets home between 4:30 and 5:30 in the afternoon. One day he comes back home late, so his mother says, "You come back home late today, Bob!" "Yes, we have got a new teacher. He teaches us Maths." Bob answers. "How is he?" his mother asks. "I don't know. I don't think I can believe him." "Why?" his mother asks. "In today's Maths class, one moment he says two and three is five. But the next moment he says one and four is five. "Bob answers.
