Dime turns into a dollar
Do you want to make some money?
OK, let’s say you have a dime.
If you square $0.10 it equals to this $ 0.01.
$(0.10)^2 = $ 0.01.
So you will get a penny 
However if you square 10 cents you get 100 cents.
(10 cents)^2 = 100 cents.
So you just earned a full dollar out of a dime 
Sent in by Virtual Val.
For the visitors who do not understand it right away, Tom has sent in this explanation:
‘Just looking at the cent into a dollar puzzle. One line reads: $(0.10)^2 = $ 0.01. This is very wrong.
1cm ^2 = .1cm x .1cm = .01 (cm^2).
Now, I don’t know what a square-dollar is, but $(0.10)^2 certainly is$^2(.01).
Anyway, I suppose the problem should be restated to ask what went wrong? or what makes this possible? and the solution should be the above.’
The problem is a rather clever mathematical illusion. The answer of a dime, .10, squared is definitely a penny. One must write a dime as .10 (or .1) - if one decides to square (10 cents) then the answer should be 100 (cents squared). “Cents squared” if it did exist, would require one to move two x two decimal places (rather than the simple 2 - i.e. 05 cents = .05). 100 “cents squared” would be equal to $.01