**Take a Number.**

Here’s a little trick that is so simple but people never seem to be able to see how easy it is. Tell some one to think of any number he likes, but not to tell you what it is. Tell them then to double it. When they have done that, let them add an even number to it, which you must give them. Any even number will work but keep it simple. After doing this, he must halve the whole, then from what is left, take away the number he first thought of. When this is completed, if he has counted correctly, you will be able to give him the exact remainder, which will be the half of the even number you told him to add to his own.

“Think of any number, but don’t tell me what it is and don’t make it too large because I’m going to ask you to do some mental math.”

“O.K., I’ve got it.” (20)

“Now double it but still don’t tell me. As a matter of fact, never tell me the number you get”

“O.K.” (40)

“All right, now add - let’s see – Oh, make it 16.”

“Got it” (56)

“Just two more things, divide your number by 2”

“O.K.” (28)

“Very good, now subtract the number you started with.”

“Done it.” (8)

“I bet you your number is 8”

“Wow! How’d you do that?”

On occasion I've taken this little trick and expanded it to a bit of magic for a small group. Say you have three or four friends sitting around and you tell them you want to demonstrate the existence of miracles by performing one and then, follow that up with a bit of mind reading. Beforehand I've prepared little squares of paper each with a separate number on one side. The numbers are all the even numbers from 2 to 20. You mix these up so some are face up and others face down and have them ready in your pocket.

Then you do the trick as above having each of the friends pick a number. I always warn them they should try to keep the numbers small because they will be doing some mental arithmetic but, since I've told them they can pick

__any__number - I don't care if it contains a hundred digits - I have some extra pencils and paper handy for anyone who insists on using a larger number. Then we start with the numbers. When I get to the point where I pick a number instead of just doing so I reach in my pocket and throw the little squares of paper on the table. They can see there are different numbers because some are face up but they never notice those they can see are all even numbers. I turn the face up ones over so now no numbers can be seen and then shuffle them around and ask one of the friends to pick out one of the squares and that is the number we use. Having done this they are aware

__they__picked the number, not I, and did so at random.

It's always amazed me how many times I've done this trick and it didn't work because the spectator screwed up the math or didn't follow the instructions exactly and, of course, this spoils the trick. So to avoid this I go through the mathematics twice with them to make sure they did everything right.

When done you tell them, "O.K, heres's the miracle. Each of you ended up with the same number but, wait, don't announce it yet. Now for a little mental magic - and I know what that number is. and then you tell the number which they all have!