Can You Answer What Is 2-2 = ?

I just what to ask a simple question from you. Can you tell me what is 2-2 equals or 3-3 equals ? What if i say that the result is not at all equal to zero. Don't think i am joking. I have a proof of it. What if i say that calculator itself will say that 2-2 is not equal to zero. I know you are still thinking that i am joking. You will be shocked to know that calculator will show you such a result which will force you to think whether you had studied the right maths in your life.

Ok so i think you will not trust me untill i show you the proof. So follow the steps:

1. Firstly open the calculator present in windows whether it is XP or windows 7 doesn't matter. Open that calculator.
2. Now type 4 and then find it's square root then subtract 2 from the result and you will be amazed to see the result. As the square root of 4 is 2 and when we subtract 2 from it the answer should be zero but it is not so. The answer is not zero.
3. Now you can try this for any number except 1. You just have to make a square root of the number and subtract the number which you get when you find the square root. For example find square root of 9 and then subtract 3 from it.

Now amaze your friends with this. Tell them that 2-2 is not zero and prove them wrong. Enjoy :)