IF you want to know how many years of HS math is needed for admission to a college you can google the school’s common data set.
IF you want to know how much math the student will need to take in college, you can look at the online course catalog and distribution requirements. Note that many colleges with distribution requirements do offer math classes geared towards non-math oriented students.
As an aside, not every college will accept courses taken online through another college or at a CC. Once a student commits to a college, any outside courses should be pre-approved (in writing).