Good one, took me a minute to realize that the mistake occurs in the step with the squares--you have to square the units as well. So what you really get is:

Good one, took me a minute to realize that the mistake occurs in the step with the squares--you have to square the units as well. So what you really get is: 0.01 (dollars)^2 = 100 (cents)^2 0.01 (dollars)^2 = 100 (1/100 dollars)^2 Taking out the 1/100 makes both sides equal.