http://www.digicc.com/fido/fido.swf

Posted on 2005-03-03 17:22:10 by bitRAKE
Very good indeed, I like to understand better how it works.
Posted on 2005-03-04 08:29:53 by Eóin
1. Pick a number (M)
2. Randomize digits in (M) to form another number (N)
3. Absolute value of (M-N) equals a multiple of nine (X)
4. Extract a non-zero number from (X) to produce (Y)
5. Randomize digits in (Y) to form answer (Z)

It is trivial to find the digit needed to add to (Z) to produce multiples of nine because the digits always sum to a multiple of nine and zero is not allowed to be excluded in step 4.

This works even at the pub for a beer (2 so far)! :lol:
this once - it really helps to know your math and science.
Posted on 2005-03-04 17:44:31 by bitRAKE

I made $20 with this once - it really helps to know your math and science.


Wow i will try this at home today.
Posted on 2005-03-05 09:45:48 by AceEmbler
it failed for me '9' while there is no 9 in sight :P
Posted on 2005-03-06 08:35:18 by Hiroshimator
Yea that is the problem with mod 9. You can't tell whether the missing digit is 0 or 9. :-D
Posted on 2005-03-06 09:56:05 by roticv
That is why is says not to circle a zero. :roll:
Posted on 2005-03-07 00:16:34 by bitRAKE
hmm, yes, i picked "111" so of course, it failed for me :)
Posted on 2005-03-08 18:37:39 by abc123