It seems that pip-boy doesn't display stats higher than 10.

Like if you took BuffOut, ate Bahmin Stake, or has Items that add to stats.

Does the game take into consideration that the stat is higher than 10? or regardless of the total bonus 10 is the highest it goes?

You cant get your SPECIAL higher than ten, even with chems or clothing.

From what I know, nothing goes over 10. So if you have a stat of 9 in something, and something boosts it by +2, then you only have 10, not 11. So anything over 10 is wasted then.

I think this is how it works.

If 9, it functions at 9.

If 9, + 2 it IS 11 but SHOWS and FUNCTIONS at 10.

If 9 + 2 (showing 10) then you mount something that is -2, you'll get 9 (not 10-2 = 8, instead it is 9 + 2 - 2 = 9)

9 + 2 IS 11 but the max is 10, so it FUNCTIONS as 10.

If 9 + 2 (showing 10) then you use something that's -2, you'll get an 8. That's how it works. SPECIAL does not exceed 10. Skills do not exceed 100.

With that logic, if I am at 9 and I mount + 2 I have 10

If I mount something else that is -2 then I am at 8 ( as you say, 10-2=8)

If I take off my +2 item then I'll be at 8-2 = 6, when all I was before this was a 9 now wearing one -2 item (should be 7, but using your math I would be at 6)

So what you are saying is you want to 'apply' the negative first and then add the bonuses.