Fun fact: I had a teacher in private elementary who would literally throw the 1" diameter pieces of chalk and Pink Pearl erasers at students who talked too much or otherwise didn't pay attention. He had deadly aim - once a student in the very back of class against a wall was talking too much and we all turned to stare at him. The chalk flew. The piece of chalk cracked in half against the wall at the exact place the kid's head would have been - if he hadn't sensed it coming and moved. Whew.