Maths fun: 1$ = 10 cent

Theorem: 1$ = 10 cent  

Proof:
We know that $1 = 100 cents

Dividing both sides by 100 we get:

$ 1/100 = 100/100 cents
=> $ 1/100 = 1 cent

Take square root of both sides we get:

 square root($1/100) = square root (1 cent)
=> $ 1/10 = 1 cent 

Multiplying both side by 10, we get
=> $1 = 10 cent   


So where lies the trick ;) ?