Santa heard his son reciting his homework:
"Two plus two, the son of a bitch is four; four plus four, the son of a bitch is eight; eight plus eight, the son of a bitch...'" "Shut up !" shouted furoius Santa. "Watch your language! You're not allowed to use the swearwords".
"But, Dad," replied the boy, "that's what the teacher taught us, and she said to recite it out loud till we learned it."
Next day Santa went right into the classroom to complain.
"Oh, heavens !" said the teacher. "That's not what I taught them. They're supposed to say, 'Two plus two, the sum of which is four.' "