Check out this bar trick of super sonic hearing. It is the trick that fooled Einstein by Brian Brushwood and Revision3's Scam School. Watch Brian scam Olympic gold medalist Jonny Moseley with a few coins, and some algebra!
EFFECT: You and your friend pull out some change from your pockets, hold the coins in your hands, and shake 'em. Without looking, and judging from the sound, you're able to accurately describe the exact difference in value between your coins and your friend's.
Method: Not sure if this is true or not, but I learned this trick as "the trick that fooled Einstein." And it's brilliant, thanks to the special phrasing of your prediction.
To pull this one off, you'll need $2.85 of change in your pocket, comprised of 10 quarters, two dimes, two nickels, and five pennies. Pull out your change, listen to their change shaking, and then confidently announce your three-part prediction: "I have as much change as you do, plus two quarters...and enough change left over to bring your total to $2.35."
There's three parts to the prediction:
1 - "I have as much change as you do" ...pull out enough of your change to exactly match your friend's amount.
2 - "plus two extra quarters" ...drop down two quarters.
3 - "and enough change left over to bring your total up to $2.35"...and sure enough, you'll find that this is exactly true, no matter how much change your friend has.
Why does it work? Because if you look at it algebraically, you're really saying "I have X + .50 + ($2.35 - X)"...If you're a math whiz, you know that essentially, you're really saying "I have $2.85," (which is not so impressive). Luckily, the phrase is able to fool just about everyone into thinking you've made an impressive prediction!