Replies

Precalculus:
The Schaum’s “Outline” series and “Solved Problems” are the better ones. I avoided “Dummy” series as I did not desire even thinking about calling myself that.
https://www.amazon.com/s?k=Schuam%27s+pre-calculus&ref=nb_sb_noss

REA Problem Solvers for Pre-Calculus: not inexpensive, possibly try used bookstores and/or eBay.
https://www.amazon.com/s?k=The+Problem+Solvers+pre-calculus&ref=nb_sb_noss

Calculus:
Schuams: even have 1 with a video included.
https://www.amazon.com/s?k=schaums+calculus&crid=2Q56Y98T1LVAI&sprefix=Schuams+calculus%2Caps%2C262&ref=nb_sb_ss_sc_1_16
Problem Solvers:
If he has to take math above Calc 1 and Calc 2, the Problem Solver Differential Equation book is useful.
https://www.amazon.com/s?k=The+Problem+Solvers+calculus&ref=nb_sb_noss_2

Calculus Made Easy
This is the one I used
https://www.amazon.com/Calculus-Made-Easy-Silvanus-Thompson/dp/0312114109/
Newer edition:
https://www.amazon.com/Calculus-Made-Easy-2020-New/dp/B08QLSWHYY/

Oliver Heaviside:
https://www.amazon.com/s?k=Oliver+Heaviside&i=stripbooks

Dr. Derbes, physics prof I had, pointed out many “smart” folks to us in his lectures including Richard Feynman, the guy who simplified the Space Shuttle Challenger disaster by placing a piece of the Morton Thiokol rubber O-ring material into a glass of ice water then removing it and breaking it showing how brittle it got under extreme cold conditions. The launch managers were exposed and the engineers they ignored were vindicated. Not listening to your workers input is a bad idea no matter where you are in life.
If your son is required to take physics, he may enjoy some of these...I did and still have them.
https://www.amazon.com/s?k=Richard+Feynman