Got a 'F' in Arithmetic

Little Johnny returns from school and tells his father he got an "F" in Arithmetic today.

"Why?" asks his father.

"The teacher asked, 'How much is 2 x 3?' I said "6".

"But that's right," said his father.

"Then she asked me 'How much is 3 x 2?'

"What's the fucking difference?" asks his father.

"That's what I said!"