A small boy came home one day and said, "Dad, I got an F in math."
"Well," the boy said, "the teacher asked me how much four times five was."
His father said, "And what did you say?"
"I told her it was twenty."
The father was puzzled. "That's the correct answer. So why did you get the F?"
The young boy's face fell. "But then the teacher asked me how much five time four was."
That's when the father began to yell. "You stupid @#$%^& idiot! Don't you know there's no difference?"
The boy said, "That's exactly what I told her."