Really, this is a very general issue with games; people don't actually want to be dealing with numbers in the course of their gaming, because every bit of math that they're required to do on the fly slows down the game. Quite frankly, people have enough trouble adding together all the numbers on their damage dice when they're up to throwing four or more dice at the same time... much less trying to figure out some real math, like an exponent. The intellectual ability or mathematical skill of the participants is mostly irrelevant; you're not trying to do math problems, you're trying to play a game. Anything that makes you focus more on arithmetic, and less on killing orcs, is something you don't actually want to do while playing a game.
From Ken Burnside, a game designer
Counting is easier than addition.
Addition is easier than subtraction.
Subtraction can be done, but combining addition and subtraction into the same game mechanic will slow down play considerably. (“I have +2 for flanking, and -2 for lighting…”) is surprisingly fiddly in play.
BIG GAP HERE
Subtraction and addition in the same operation is easier than most forms of multiplication. For example, it’s better to express a critical hit as “+100% damage” rather than “x2″ damage. Not only does it avoid edge cases (where you have two critical hit multipliers that both apply) it’s faster at the gaming table because it’s addition.Multiplication by 10, 5, 4 and 2 are light weight enough to be usable. If you’re using a multiplicative operator other than one of those four digits, you need to change something earlier in the process. When in doubt, make it addition.
BIGGER GAP HERE
Division is only tolerable when A) you’re dividing an integer and expect an integer outcome, or are rounding to an integer outcome, and B) the divisor is 2 or 10. I specifically built some parts of my games for modulus division to avoid these problem.
GINORMOUS GAP HERE
Square roots, cube roots and exponentiation are probably not game friendly to most people. When in doubt, transform your equations to use one of the first two items on this list.
My impression is that Ken's games are geeky, so it's reasonable to assume his players are more adept with arithmetic than most people. I'm posting this because it might be worth knowing for anyone who's trying to explain something that involves numbers.