How much math skill can an RPG expect from its players?
As a kid of 11-12 years old when I discovered RPG's and one who was NEVER excited about (and on some level was afraid of) math? RPG's helped me get over my fear of it. So much so that once I became comfortable with adding and subtracting relatively quickly in my head, multiplying and dividing were next. I played Basic then Advanced (1st then 2nd ed) D&D, Star Frontiers, Top Secret and Marvel Super Heroes (FASERIP). We graduated on to DC HEROES, Traveller, TMNT & Other Strangeness and Champions 4th Edition.
At no point did any one who I played with ever complain or had issues with math. Complaining about the fact that there was "too much", or that it interfered with role playing or any of the things that people are complaining about now. I think that we understood that these were role-playing GAMES and the math and the role-playing went hand in hand.
Admittedly not everyone had the mind set to deal with building mecha in R. Talsorian's MEKTON II or MEKTON ZETA, but griping about adding and subtracting modifiers? adding and subtracting hit points? Using hyperbole to deride games like Pathfinder (MATHFINDER? REALLY?), saying that D&D 5E is math heavy or crunchy? Really?
For me it's not how much math skill can I expect from it's players, it's the players that I want at the table to understand that math is part of the game, especially games that are combat heavy/focused like D&D and Pathfinder. We didnt have smartphones back when I started playing, we used scrap paper and sometimes our calculators (if we had them). Today, if you have a smartphone you have a very powerful mini computer IN YOUR POCKET.
You can LITERALLY (VERBALLY) ASK your phone (if you have siri) to do a calculation for you and it will GIVE you the answer.
No one is asking any of the players to draft a masters thesis on whether 0 is a number or not. It's addition, subtraction and at most division or multiplication. If you cant handle that? Then I dont know what to tell you.
And frequency isnt as big as a factor either. There are a MILLION other things that slow down things at a gaming table. The problem is that people aren't willing to do simple things like if they know they have a modifier to swing a sword? Just add together whatever those base modifiers in advance and just add that to your die roll. Know what your character ACTUALLY DOES before hand instead of waiting until it's your turn to figure it out. A lot of the complaints that I see have more to do with being unable to manage a character sheet than the math itself.
The one thing that might be valid are adding a bunch of dice together from dice pool games and massive D6 damage dice. But that's where help from your teammates or fellow players come in.
And in the case of those who are legitimately scared of or have issues with math? Calculator. Or seek assistance from a player who is less afraid of math. We're all here to help each other and have fun anyway right? I used to BE that kid who wasn't good at and to an extent was afraid of math so I GET IT.
I also think that VTT's have helped mitigate a lot of the math issues on some of the crunchier games.
In short, maybe I'm a bit of a snob, but if adding and subtracting numbers together at a 3rd or 4th grade level is a daunting task for you? AND you have a powerful computer in your pocket but for some reason dont want to use it? I'm not sure I want you at any table I'm running a game at. The first thing I have some empathy for, I REALLY DO so as a GM I'll work with you. The second? It seems that you just want to make things harder for yourself to have something to complain about.