Trick Calculator

Trick Calculator can do basic calculations.
But!
If you ask a friend to type in a secret number, then multiply it by his age or this year, or anything you can think of, then continue calculating as long as you want to play the joke.
The end result will be the SECRET NUMBER!
You just have to remember two things.
1. First the secret number, then times (X).
2. The last thing has to be Squared (X2).
When they press equal, there's the SECRET NUMBER!
If you forget these instructions, hold down the 5 key and the instructions will magically appear.