http://flashlightcreative.net/swf/ghostwhisperer is a website that claims it can read your mind.
As you can see from the picture above, the Ghost Whisperer asks you to pick a two-digit number, add the digits, and then subtract your total from the original number you picked. Find the symbol next to the final number on the chart, concentrate on it, and click on the crystal ball. The weird (and slightly spooky, perhaps?) thing is that it is always right. But this website is not triggered by what symbol you hover over the most, nor is it psychic.
How does it work then? Well, that is what my teacher asked the class. Each table was a team, and once you figured it out you had to explain your answer on a poster to hang in the hallway. Here is the poster my team made.
(We hadn't added the QR code yet)
So, what is the answer? Well, there is a teensy-weensy little detail which probably goes over the head of most users of Ghost Whisperer. If you look closely you may notice that some numbers have the same symbol. But if you look even closer you might notice that all multiples of 9 (besides 90 and 99, since the highest possible final number you can get is 81) have the same symbol, even though every time you use Ghost Whisperer the symbols change!
And, sure enough, no matter what two digit number you pick once you put it through the whole Ghost Whisperer process- add the digits, subtract that from your original number, e.t.c - your final number will always be a multiple of 9! So that way, all your crystal ball has to do is show the symbol assigned to the multiples of 9! (Excluding 90 and 99, of course.)
This was a very fun project to do, and a cool puzzle to figure out. And, as an added bonus, now I know about the Ghost Whisperer, I can show my friends an awesome website.
Anyway, I hope you like these posts, and don't forget to comment!