How does this work?

[russotto]

Originally posted by blowmeetheclown
The first time I tried it, I got 'x,' which was correct. Every time after that, I got 'm.' This was also correct, but I tried to go back and figure out what I chose to get 'x' the first time, and couldn't remember. I guess I'll have to do the math...

They change the symbols. But all the multiples of 9 will always have the same symbol.