Heh, it’d be a funny test if you say if someone can’t give the correct answer to 2+2 you won’t play with them.
I think with math you can communicate with people in a very logical manner. Even with just basic addition.
Unless they can’t give the right answer, of course. Then hey, as said, don’t play with them.
Otherwise all excuses that people don’t read rules or they do whatever and that’s the game and people aren’t logical – it’s rubbish. There are ways of getting through and either you didn’t really try, or you like it being confused.
Oh, and a post on peeling back the graphics of your fave game, on my other blog: http://philosophergamer.blogspot.com/2010/05/if-you-stripped-you-fave-game-bare-of.html