Find a four-digit number with four different digits, that is equal to the number formed by its digits in descending order minus the number formed by its digits in ascending order.
(In reply to
re: divisible by 9 proof :) by Gamer)
Yes, it's the proof via backwards-thinking. ;)
It' still amazing that the positioning of the previous-to-last digit automatically sets the last digit right according to the rules.
We still have a hard time to find an explanation for this.
|
|
Posted by abc
on 2003-09-12 20:38:23 |
re(2): divisible by 9 proof :)
