I am slightly perplexed. Mind reader. How does it work??
 

Check it out yourselves.

http://www.albinoblacksheep.com/flash/mind

No idea.
kind of spooky isn't it?

it's simple, there is a limited number of numbers:

11= 11-2=9
12= 12-3=9
..
44= 44-8=36
45= 45-9=36

etc.

You will see that these numbers all have the same symbol in the table

No matter what number you choose, when you do the suggested math you will always get 9, 18, 27, 36, 45, 54, 63, 72, 81 or 99. They are all multiples of 9. It's a simple math property.

The trick is, if you notice, every time you click the button those numbers are the same symbol, and they change every time. But they always match each other, so no matter what you pick the symbol will be what it says. It's tricky, but easy to understand once you see it.

I get it. Thanks. Thats a neat trick.

math can be fun