http://www.dslextreme.com/users/exstatica/psychic.swf
Wow

Old.

If I had the time to figure out how it did it again, I would, but I'm lazy.

I tryed to confuse it, and it works and sometimes it doesn't. :-X

Its worked every single time for me.

1 + 2 = 3, 12 - 3 = 9
2 + 3 = 5, 23 - 5 = 18
3 + 4 = 7, 34 - 7 = 27
4 + 5 = 9, 45 - 9 = 36
....

Notice how those numbers (farthest on right) always have same icon

I spent about 20 minutes one raininy day working it out, and theres a pattern. Its very clever though.

Yeah, it'll always work out to multiples of 9, just like UserLoser said, and the multiples of 9 are all the same icon every time.  But it's a different icon each time you play, which is the sneaky part.

yea
the symbol that shows up over and over
just happens to be every multiple of 9

;')

I don't know why this amazes so many people. It's the simplest thing ever.

You pick a two digit number: "xy", value: 10x + y
Sum of digits: x + y
Number minus sum of digits: (10x + y) - (x + y) = 9x
Result divisible by 9.