A reasonably smart student can use a combination of Khan Academy (free) and Brilliant.org ($120/year to access course content and problems) to get a well rounded understanding of math and science up to the sophomore college level. Throw in a workbook or two for rote practice of trig identities, integrals, etc. Add a home lab kit or two and a few field trips when necessary. And boom... you’re set for years.
Shaum's Outlines are really quite good in this regard. Hundreds of practice problems with answers, so the student can check.