Tangentially related to your question, but I figured it might help if you need to review math at some point. Given it has been a while since you last did math courses, I have a non-free book on CALCULUS[1] and another one on LINEAR ALGEBRA[2] that are written specifically for adults who need a condensed (but complete) review of the material. See PDF previews below.
Yes, the long previews are intentional. Basically I wanted to have a full chapter from each book, then went through the rest of the book to select pages with topics that looked interesting, so I ends up with 100+ pages.
The full books are 600pp and 700pp respectively (on small paper format 5.5"x8.5")