Calvin and Hobbes by Bill Watterson for November 04, 1988
Calvin: Mom said I can't go outside until I finish my homework. If you'll help me, I'll be done faster. What's five plus seven? Hobbes: I don't know. Calvin: I don't either. Hobbes: Then write, "I don't know." Calvin: Hey, that's a true answer, isn't it! I can write that for all of these! We're done! Parent: We'd better have a look at our prodigy's homework.