You don't have to be good at math to play a rogue. Anyone can log into WoW and create a rogue. You can get all the way to level 90 and into raids without ever having to do any addition or long division. You can do dailies and dungeons simply by using the highest ilvl gear available and ignoring everything else. Rogues are played with a keyboard and mouse, not a pen and paper.
However, if you want to wring every last drop of DPS out of the class, you're going to have to get your hands dirty with numbers. I love when a class' design forces the player to make tough choices. The choices that we make as rogues, when you think about it, are really just math problems. The secret to making good choices is to do the math ahead of time. You don't want to be faced with an unexpected set of fractions in the middle of a tough raid encounter.