In Oklahoma, the requirement usually is up to “algebra 2” - this is mostly domain and range, finding roots of polynomials, and logarithms.
IMHO, the world would be better if calculus was a required part of the high school curriculum. Like yeah, most people aren’t going to need the product rule in day to day life, but the fundamental ideas about rates of change seem like they’re something that everyone human deserves to be exposed to.
if he can get that far into calculus, he wouldnt be having problem with math skills. its the people struggling with aritmetic, or early algebra thats problematic. i think the early books in ALG1 and 2 and geo, are just a little to convoluted for people to learn, because its mostly abstract word problems. plus the teachers in our HS dont even teach the subject properly at all, they expect you to know how to do it already in the early 2000s. same went for chemistry, and adv algebra, just poor teaching skills at least in our school. hence why alot of hs comes out with such poor math skills.