That is what I do every day. I do love teaching math. If you’d like to read more about what I’ve found awesome in math, check out my math wiki.
If you’re interested in learning about math, regardless if you’re in school or out, you may be interested in open source textbooks. Education for free! What an excellent idea. Textbooks are horribly overpriced. It’s not like math solutions are somehow proprietary. Sure, the way an author describes out to solve the problem may change slightly and the video and support structures change from publisher to publisher, but really 1+1 is still 2, no matter who is selling the book.