Well I'll break our my math usage some.
I have to know how to do order operations and word problems - after all that is what brewing is. I frequently use calculators to work out that 6lb of DME and adding 2lb of honey after I've been fermenting a couple of days to get an calculated OG etc.
I'll do some math by hand, but nowhere near as much as I once did.
And a lot of math I've left disused (I've probably forgotten more math than I currently used.) Understand besides HS math (basic arithmatic, algerbra, trig, geometery) I also learned Calc, differential equations, basic statistics- a real requirement for some physics, linear algerbra, and complex numbers.
To day I'm probably using just some algrebra, geometry, basic trig and arithmatic.... ex. how much siding should my house need? well there is surface area -geometry+ algrebra+arithmatic, oh wait, angles for the roof, yup trig....