How long would it take

If I studied like 6-8 hours a day to learn
- Fractions
- Algebra
- Pythagoras Theoreom
- Ratios & rates
- Area & volume

Depends on how bright you are I guess, and whether you're reviewing or starting fresh.

-Pythag Theorem: An hour at the most, its one equation.

-Area & Volume: Once again its basically just memorizing equations. Shouldn't take long.

-Fractions: Adding, Subtracting, Dividing, Multiply, Reducing and all that other jazz, I'd say probably a day, maybe 2.

-Ratios: If you know fractions, you know this.  Call it a day for a little extra info and some review time too.

-Algebra: Heres the tough bit to estimate. If you mean starting with only what's above and learning all the way through AlgebraII/trig, could take 6months to a year.  But if you only want to learn how to solve for variables and a few other basics, probably a few weeks.

fractions: 5 minutes. just need know what they are, when they are equal, how to add subract. etc.

algebra: you don't wanna go there, advanced stuff like groups, rings, non commutative rings will take you years.

Pythogoras Theorem: 5 mins. works in vector spaces and inner product spaces.

ratios and rates: fractions.

area and volume: 2 mins if you just learn the forlumae. half a year if you wanna start calculus from scratch and then apply it to find the are and volume.