[NeoCaveman]

it was wrong at least twice for me, also. hard to know how it is supposed to work. i am waiting for robt to tell us that.

Take any two didgit number and subtract the sum. The answer is always divisible by 9. The answer can only be 9,18,27,36,45,54,63,72, or 81

[secret garden]

Dubs, are you our new math tutor? We've been needing a few of them in here. A+ on the extra credit!