A little boy was doing his math homework.

He said to himself, Two plus five, that son of a bitch is seven. Three plus six, that son of a bitch is nine.

His mother heard what he was saying and was shocked. What are you doing? she asked.

The little boy answered, Im just doing my math homework, Mum.

And this is how your teacher taught you to do it? the mother asked.

Yes, he answered, thats exactly how I was taught.

Infuriated, the mother went to the classroom the next morning to talk to the teacher.

What are you teaching my son in math? she demanded to know.

The teacher replied, Right now, we are learning addition.

I know that, the mother said. But I want to know are you teaching them to say two plus two, that son of a bitch is four?

After the teacher stopped laughing, she was able to answer. What I taught them was, two plus two, THE SUM OF WHICH, is four.