# Mathemagic

#### Crede

I've known about this guy for a while...you're right, his shows are absolutely incredible. I wouldn't necessarily use the word fooled though-- he's not accomplishing these great feats but trickery of any manner, just methods for fast math calculation (most of which are published, by the way), which with (a great deal) of practice, anyone can learn.

I especially love his performance style, the small jokes he throws in. "Let me recap" *caps pen* That had me cracking up.

#### Crede

For example, it's fairly easy (and I'm about to teach you, so skip if you don't like math) to multiply any 2-digit number by 11. You merely and together the 2 digits, and insert that number between them.

For example, in my head right now, 54x11=594, because 5+4=9, and I just but that between the 5 and 4. Checking with a calculator, it's right.

For digits that add to 10 or more, say, the number 74x11, you merely add a 1 the the one's digit (in this case, 7), and insert the second digit in between. So 7+4=11, 1+7=8, so the answer is 814. Again, checking with a calculator, and it's right.

So there, you just learned a simple but powerful "mathmagic" trick! With practice, you can go really fast.

PS: No idea if this could be used in an actual magic effect (mentalism maybe?) or not, but someone could investigate...

#### William Draven

I just love his comment to Lennert about not worrying that people will start doing his show next week.

#### AndyW

I guess fooled isn't the best word for this performance. I was definitely entertained and wowed though. I appreciate your explanation of how it works, but entertainment/magic isn't always about knowing HOW it's done, but appreciating the execution and perfection of the method.

#### ChrisWiens

Great!

But there is someone who impressed me even more.
http://en.wikipedia.org/wiki/Gert_Mittring
His actual record is the 98789.root of a one million digit number.
I`ve seen it live on TV not long ago.

Impressed is the right word. I appreciate their skill, but it`s not magic to me.
Real mathemagic to me is, for example, what Scarne, Elmsley or Woody Aragon did. Using mathematical principles as another tool in your arsenal to confront people with the impossible in a way that they will not have a single clue how it is done or that it could be done.

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#### Crede

Yeah, it was very entertaining and very impressive. You can only imagine how much work he has put into that, especially because the numbers he's given are different each time he performs.

My apologies, perhaps I shouldn't have explained the method behind that simple calculation then...although keep in mind, that really is a simple and widely known "lightning calculation", as they're often called. I agree with you that appreciating the execution and perfection is important...I suppose I was explaining a tidbit of mathmagic because at one time, I was fairly interested in this kind of stuff, and still am. Not, of course, to the extent that Mr. Benjamin is, but I have in the past practices mathemagic techniques.

Again, as for your ideas about why we enjoy entertainment and magic, I completely agree.

#### AndyW

Revealing the "method" is fine, it is easily attainable information from a google search. It's amazing though how fast people make these calculations in their head. I too, am fascinated by math so it's fun seeing it an magic together. I know it isn't a traditional magic act, but his skill is something magical and rare.

#### JDENredden

Arthur Benjamin has a book teaching his methods for Mathemagic.

And while you can say 'Oh, its just simple 'Lighting Calculation'', but when you see what he does to do those harder ones near the end its not as simple as you think. Simpler then you'd think but still ridiculously hard.

Its like all skill. You can take the stance and say anyone can do if they practice.

J.

#### JD

The birthday effect is in 13 Steps.

#### Jewish_Illusion

I actually saw Arthur Benjamin live once at a university and he did the magic square effect, except he failed.
still, im not any less impressed