Teachers have no sense of humour and some of them seem to have no sense at all.
Classic case in point.
Little Johnny comes home from schoolnsfw
He says to his father, "Dad, our math teacher is asking to see you."

"What happened?" the father asks.

"Well, she asks me, 'how much is 7x9?' I answer '63' , then she asks, 'and 9x7?' so I asked 'what's the fucking difference?' "

"What is the difference?" asks the father. ''Sure, I'll go.''

The next day, Johnny comes home from school "Dad, have you gone by the school?" He asks.

"Not yet."

"Well when you do, come and see the gym teacher also."

"Why?" asks the father.

Johnny explains, "Well, we had a gym class today, and he asked me to raise my left arm, I did. Then my right arm, I also raised it. Then he asked me to lift my right leg, so I did. 'Now,' he says, 'lift your left leg,' so I asked 'The fuck am I suppose to do, stand on my dick!?'"

"Exactly," says the father. "Alright, I'll come."

The next day, Little Johnny asks his father "Did you go to the school?"

"No, not yet."

"Don't bother, I got expelled."

Surprised, the father asks "Why did you get expelled?"

"Well, they summoned me to the principal's office, and sitting there were the math teacher, the gym teacher, and the art teacher."

"The fuck was the art teacher doing there?" asks the father.

"That's what I asked!" said Little Johnny.