The son of bitch

A little boy was doing his maths homework, saying to himself, 2+5 the son of bitch is 7.. 3+6 the son of bitch is 9.

His mother heared this & gasped "what are you doing?" the little boy answered, "I'm doing my math's homework Mom."
"And this is how your teacher taught you to do it?"
"Yes", he answered.

Infuriated, the mother asked the teacher next day,
"Are you teaching maths to children by saying 2+2, the son of bitch is 4?"
the teacher started laughing, and answered "what I taught them was, 2+2 THE SUM OF WHICH IS 4".
These kids! :p