Let's face it, there was always somebody at school who couldn't wait to point out to the teacher when he/she had made a mistake on the blackboard.
Strangely enough it always seemed to be the same two or three individuals.
Even at that age I was always of the opinion, "look, you know what she means, so put your hand down and let it go."
I also seem to remember the teachers getting quite irritated at being corrected...wonder why?

On a slightly different not, I recall the footballer Paul Gascoigne picking up the referee's yellow card after he had dropped it during the game. Before returning it to him, Gascoigne held it up as if he was booking the ref'. The official took the card off the smiling player and, with a face like fizz, returned the gesture and actually booked him for real.
It was a Scottish ref' though so that might explain it.
