As part of a punishment, you may be asked to decide the punishment yourself. The teacher will then decide whether you've opted for a harsh enough sentence, and may add humourous tweaks, if he's that sort of teacher.

Tactics for the student varied, opting for an exagerrated sentence would show that you recognised the severity of your sins, but you ran the risk of the teacher agreeing with you.

Alternately, you could try saying "you could make me go home, sir" - or "you could give me three millions pounds so I can go mental on drugs and end up dead", in the hope that such cheeky-chappery will make the teacher say "dooo, I couldn't possibly punish you... you have such spirit", before lovingly chasing you around the classroom.