A little boy took his dog on a "take your pet to school" day. There were prizes for the smallest, the prettiest, the cutest, and the smartest pet. Determined that his dog win a prize, the boy put his pet through a whole series of tricks.
Finally the boy turned to the dog and asked, "Maxy, how much is two plus two minus four?" The dog sat quietly, making no sound, remaining still and silent. "Right!"
exclaimed the boy. His dog won first prize.