Try this little game out! Then let me know how they do it :shrug: http://www.quizyourprofile.com/guessyournumber.swf
That's not very hard. It's just elimination. 5 numbers per colour. You tell it the colour so it has 5 options only already. Then all 5 numbers are spread in 5 houses and by choosing the house, it's enough to tell. I like this one better, it's a little math trick: http://www.mysticalball.com/
The only parts that matter are choosing the colour of the number in the first step and choosing the number in the house. These two steps allow the program to determine the number you chose. The rest is just window dressing. With the doors, of course, the program can put your number behind any door (or, equivalently, all of them).
That's kind of a simple one, the number will always be in the nine times table and they always all have the same symbol. So long as you know how to do math it can't be wrong.
