How on earth does this work?

[palmer_eldritch]

This is a Flash version of a magic trick where the magician - in this case the computer - guesses what you are thinking about. And it works, at least on me. It guesses the number you are thinking about, without having you input anything at all.

You'd have to try it to understand. It's worksafe, although it does make a silly noise so your boss may not approve if they hear it.

http://www.milaadesign.com/wizardy.html

Can anyone explain how it works? It's really bugging me. I reckoned if anyone could come up with the answer it would be someone here.

Btw to answer anyone who wonders who the hell are you, I am some guy that used to be part of "the community" back in the days of LtM and lurks here sometimes . . . hoping someday someone will announce a decent new mmog has come out.

[WayAbvPar]

I have seen similar things and have heard an explanation, but I cannot recall for the life of me what it is. Obviously there are only a few symbols to choose from, but that is as far as I have gotten. Brilliant, no?

[Strazos]

Apparently, any 2 digit number, when you subtract from it the sum of the 2 digits, is always a multiple of 9. I believe the tables will always have the same symbol for all the multiples of 9.

Or so I am told.

[WayAbvPar]

That makes sense. I noticed that the multiples of 9 all had the same symbol, but didn't go any further.

[Nebu]

Apparently, any 2 digit number, when you subtract from it the sum of the 2 digits, is always a multiple of 9. I believe the tables will always have the same symbol for all the multiples of 9.

Or so I am told.

You type faster than I do.  Yes, that's it.  All multiples of 9 have the same symbol and that trick will always produce a number divisible by 9.  

Take 36.  36 - (3+6) = 27 or 9 x 3

Take 44.  44 - (4+4) = 36 or 9 x 4.  

See. Math IS fun!

[Merusk]

Curses too slow, I was in the middle of posting just that.

Margalis explained it to us when Strazos posted it last time.

[Strazos]

My way was quicker than using the search function to dig up that thread.

[palmer_eldritch]

Ah yes . . . I did it twice and got two different symbols, both of which were correct for the different numbers I had chosen each time. That really threw me.

But - now I have looked at it again, I see they have two symbols for multiples of nine, and I guess it just chooses one at random, giving it a 50 per cent chance of success.

Thanks. It really was bugging me!

[Righ]

Btw to answer anyone who wonders who the hell are you, I am some guy that used to be part of "the community" back in the days of LtM and lurks here sometimes . . . hoping someday someone will announce a decent new mmog has come out.

I like your forum name.

[Morfiend]

Ah yes . . . I did it twice and got two different symbols, both of which were correct for the different numbers I had chosen each time. That really threw me.

But - now I have looked at it again, I see they have two symbols for multiples of nine, and I guess it just chooses one at random, giving it a 50 per cent chance of success.

Thanks. It really was bugging me!

I did it 4 times, and got 4 different symbols, and each time it was correct. So the 50/50 thing is wrong.

[Nebu]

Looked it over.  All symbols for multiples of 9 that are possible with this method were there.  99-18 = 81.  So the symbols for 9, 18, 27, 36, 45, 54, 63, 72, and 81 were the same.