It was a Sunday morning. Peter was watching TV in the room while his brother Bill was doing his homework. At ten their mother came back with a bag of oranges. Peter liked them and wanted to eat them quickly. But his mother stopped him. She gave five to each son and went to the kitchen. Peter ate his oranges soon but his brother was busy doing his homework and didn't eat his. Just then, the telephone rang and Bill ran to answer it. Bill's friends asked him to play soccer with them. And when Bill talked with his friend, Peter took two of his oranges away and ate them. Bill found it and called him out and beat him behind the house. Peter didn't tell his parents about it.
The next morning Peter's teacher, Mrs Ball, taught the students subtraction(减法). Peter was looking at the bird in the tree out of the window and couldn't answer her questions. The teacher started to give him an example," If your brother has five oranges and you take two from him, what will the result be?"
"He'll beat me, teacher," answered the boy. All his classmates started to laugh.