The comic strip Frazz features an extremely annoying child named Caulfield. In today's strip (select for a larger version) he once again tries to get over on the system. If he were my student, he'd learn about averages all right. "100 for Wednesday's, which you did, and 0 for Thursday's, which you did not do. That's 50%." "I did it!" "Perhaps, but you turned it in on Friday, and the grades were posted Thursday. When it was due."