Calvin and Hobbes by Bill Watterson for December 02, 1989
Hobbes: Doing homework? Calvin: Yeahhhh....boy, you missed the show. I got a big lecture from Mom just because I got stuck on the ceiling and the grew so big I fell off the planet when I was supposed to be doing my math! Hobbes: Gee, that's not very fair. Calvin: You said it. Here, how about helping me with these problems? Hobbes: Sure! Tigers are great at math! Now what do these little horizontal lines mean? Calvin: That's a minus sign. Let me know when you're done, Ok? I'll be reading comic books.