Thanks for the other recommendations. DS is concurrently doing the Khan algebra lecture sequence and using the Harold Jacobs algebra textbook to get ready for Epsilon camp at the end of summer. Any free-time math reading you all can tell me about is much appreciated.
This is going to be a math-centric summer! (per DS's request) Since I am not mathy, I need help from you all
For example, Catalana, you said you thought the LoF books were a hoot, but my eyes glazed over and my brain went slack when I browsed it! We are dealing with a rock-bottom math person trying to guide a mathy kid here!!