F in maths!

Johnny returns from school and says he got an F in arithmetics.
"Why?", asks the father.
"The teacher asked `How much is 2x3?` I said `6`"
"But that`s right!", the father says.
"Then she asked me `How much is 3x2?`"
"What`s the fucking difference?", the father enquires.
"That`s exactly what I said." right!", the father says.
"Then she asked me `How much is 3x2?`"
"What`s the fucking difference?", the father enquires.
"That`s exactly what I said."