Number Compliment

Q: What did the number zero say to the number eight?
A: "Nice belt."

Dollars Equals Cents

Theorem: 1$ = 1c. Proof: And another that gives you a sense of money disappearing. 1$ = 100c= (10c)^2= (0.1$)^2= 0.01$= 1c.
Here $ means dollars and c means cents. This one is scary in that I have seen PhD's in math who were unable to see what was wrong with this one. Actually I am crossposting this to sci.physics because I think that the latter makes a very nice introduction to the importance of keeping track of your dimensions.

Kid Math

Mom + Dad - Rubber = U