1. Jan 18, 2006

### Esnas

Can any of you out there explain how this works. I tried it a dozen times. It seems to always work!!

Last edited by a moderator: May 2, 2017
2. Jan 18, 2006

### JamesU

the result always comes up as 82, 72, 63, 54, 45, 36, 33, 27, 22, 18, 9, or 0. They all have the same symbol

3. Jan 18, 2006

### z-component

yomamma's on the right track. Everytime you come up with a number according to how they make you compute it, it is always a multiple of 9. So, every number that's a multiple of 9 will have the same symbol. Pretty tricky, eh?

4. Jan 19, 2006

### Jimmy Snyder

Specifically, let x be the first digit of your number and y be the second digit. For instance, if you choose the number 52, then x = 5 and y = 2. Then the number you need to look up is:

10x + y - (x + y) = 9x

For instance for 52, x = 5, y = 2. Add 5 and 2 for 7 and subtract it from 52:

52 - 7 = 45 = 9 * 5 = 9 * x

5. Jan 19, 2006

### Esnas

Nice going folks! Thanks. What makes this tricky is that the symbols seem to change randomly yet they are always the same for multiples of nine.