From: Benjamin.J.Tilly@dartmouth.edu (Benjamin J. Tilly)

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...