The Guide to Appearances of Mathematics on the Simpsons. I never realized math appeared so much.

Nelson:  Hey, look at what Skinner makes – $25,000 a year!
Bart:  [using calculator] Let’s see.  He’s 40 years old, times 25 grand … whoa, he’s a millionaire!
Skinner:  I wasn’t a principal when I was one!
Nelson:  Plus, in the summer, he paints houses!
Milhouse:  He’s a billionaire!
Skinner:  If I were a billionaire, why would I be living with my mother?

[ From Slashdot ]