A crazy guy jumps onto a table in a crowded restaurant and starts screaming: "I will multiply you! I will divide you!" People scatter every which way in a panic, except for a little old man in a corner, who calmly continues eating. The crazy guy yells into the old man's face, again: "I will multiply you! I will divide you!" The old man calmly replies: "Go right ahead, son. I am zero."