Khan Academy Two main reasons why it's better than other resources for your use case: - it covers everything from pre-school arithmetic all the way up to mult

Khan Academy Two main reasons why it's better than other resources for your use case: - it covers everything from pre-school arithmetic all the way up to multivariable calculus. This means that you can pick up from the level that you're comfortable at and build up from there - Sal (who delivers most of the tutorials) teaches in a very approachable way and doesn't mind overexplaining basic things that university lectures tend to skim over Once you're past Khan Academy, you can get some undergraduate/postgraduate lectures from MIT or just textbooks if you're interested in more rigorous treatment of mathematics or more advanced subfields.