Math Magic
http://www.themagicteacher.com/articles/664/1/Math-Magic/Page1.html
marvin loraya
I just started to learn magic tricks at the age of 12. I don't know many tricks, but, I hope the tricks I share will be very fun and amusing!! By marvin loraya
Published on 03/25/2008
You ask a person to choose any number without saying it to you, then you ask him/her a bunch of math operations. Then after asking, you found the answer without knowing what is the number your spectator chose!!
Math Magic Trick
Effect:Guess the answer to a math operation without knowing the number your spectator chose.
Secret:The answer will be half of the number you told your spectator to add.
Method:Ok. Ask a person to choose any number from 1 to 100(w/o telling you of course). Let's say he chose 16. Then, tell the person to multiply the number he chose by 2. Here comes the secret. Make him add the answer of the previous operation to any number YOU choose. Let's say you chose 12. So, after he has done that, let him divide the answer by 2. Then, let him subtract the answer with the number he chose. The answer will be half of the number you told you spectator to add. Here's the equation:
16 x 2 = 32 + 12 = 44 / 2 = 22 - 16 = 6.
The answer is 6. Half of 12 is 6.