


walt fristoe
SFN Regular
USA
505 Posts 
Posted  06/28/2006 : 19:49:19

I'm sure there's a matematical trick to this, having to do I think with the number 9, but I can't quite seem to pin down the details. I know that when the two digits are added together, and then subtracted from the original number, the result will always be divisible by 9. But how does the particular number match the symbol?
[edit:] Silly me, I forgot to include the link! Here it is: http://www.milaadesign.com/wizardy.html [/edit]

"If God chose George Bus of all the people in the world, how good could God be?" Bill Maher 
Edited by  walt fristoe on 06/29/2006 14:36:13


Kil
Evil Skeptic
USA
13476 Posts 
Posted  06/28/2006 : 19:57:51 [Permalink]

quote: Originally posted by walt fristoe
I'm sure there's a matematical trick to this, having to do I think with the number 9, but I can't quite seem to pin down the details. I know that when the two digits are added together, and then subtracted from the original number, the result will always be divisible by 9. But how does the particular number match the symbol?
Hey Walt, you want to supply a link? 
Uncertainty may make you uncomfortable. Certainty makes you ridiculous.
Why not question something for a change?
Genetic Literacy Project 


woolytoad
Skeptic Friend
313 Posts 
Posted  06/28/2006 : 21:24:29 [Permalink]

Thinking a bit I came up with: For any 2 digit number, if you add the digits and subtract the result from the original number, the result is always divisible by 9.
10  1 = 9
27  9 = 18
71  8 = 63
For any 2 digit number, let us represent the number value by x and y respectivly.
Thus the actual number is 10x + y. eg 23 = 2*10 + 3
Our equation is thus
10x + y  (x + y) = 10x x + y  y = 9x
QED 


Giltwist
Skeptic Friend
USA
69 Posts 
Posted  06/28/2006 : 21:42:23 [Permalink]

That's absolutely right. Questions like this are part of a branch of mathematics called Number Theory. Absolutely interesting stuff and it all is basic arithmetic give or take modulus. RSA Encryption is actually something I was shown how to do in Number Theory. It's actually really smart, and only really breakable by a brute force, try every possibility til it works way. Use a couple of 11 digit prime numbers as the basis for the encryption and we're talking significant computer time to break. 



Ricky
SFN Die Hard
USA
4907 Posts 

Wendy
SFN Regular
USA
614 Posts 
Posted  06/29/2006 : 07:18:32 [Permalink]

quote: Originally posted by Ricky
I believe I know the trick you're talking about. Look at each multiple of nine. They will all have the same symbol. So when you follow the steps, you always end up with a multiple of nine, and thus, always get the same symbol for no matter what number you choose..
Right, and each time you do it again the symbol changes so it takes longer to see the pattern.

Millions long for immortality who don't know what to do on a rainy afternoon.  Susan Ertz



Wendy
SFN Regular
USA
614 Posts 
Posted  06/29/2006 : 07:27:57 [Permalink]

Here are links to a couple I've used on my kids: Crystal Ball and Sprite

Millions long for immortality who don't know what to do on a rainy afternoon.  Susan Ertz



Dave W.
Info Junkie
USA
26020 Posts 

Wendy
SFN Regular
USA
614 Posts 
Posted  06/29/2006 : 08:02:16 [Permalink]

quote: Originally posted by Dave W.
Here's a link to one of them.
That's the link I was looking for! Didn't we have a thread on that one, Dave W.? I can't find it, but I'm sure I remember it. 
Millions long for immortality who don't know what to do on a rainy afternoon.  Susan Ertz



walt fristoe
SFN Regular
USA
505 Posts 
Posted  06/29/2006 : 15:11:11 [Permalink]

quote: Originally posted by Dave W.
Here's a link to one of them.
That's very much like the one I meant to post, just a different look.
You still ROCK Dave! 
"If God chose George Bus of all the people in the world, how good could God be?" Bill Maher 


Dave W.
Info Junkie
USA
26020 Posts 

Wendy
SFN Regular
USA
614 Posts 
Posted  06/30/2006 : 08:25:49 [Permalink]

D'oh! No wonder this seemed so familiar. Damn, I'm getting old!
(Note: The link in the old thread no longer works.)

Millions long for immortality who don't know what to do on a rainy afternoon.  Susan Ertz



Dave W.
Info Junkie
USA
26020 Posts 

beskeptigal
SFN Die Hard
USA
3834 Posts 
Posted  07/02/2006 : 20:02:03 [Permalink]

I like the witch theme, though. 




