Unfortunately, not much. I was pondering that after my post. It's been a long time since I was a math student, and professionally it's had zero to do with my career. A lot of books ended up boxed up at my parents' home as I moved around a number of times right after college. I'll check my own home tonight to see what I still have, but my shelves these days are mostly filled with fiction, programming, RPG, and history books.

EDIT:

Off the top of my head, for CS:

Introduction to Algorithms: https://mitpress.mit.edu/books/introduction-algorithms

Introduction to the Theory of Computation: http://www.amazon.com/Introduction-Theory-Computation-Michae...

Math:

Calculus Made Easy: http://www.amazon.com/gp/product/0312185480?ref_=cm_lmf_tit_... - I'm really not sure how good this one is for a beginner, I picked it up while assisting my sister in refreshing her calculus skills for grad school (Aerospace Engineering)

I can't remember the algebra and geometry textbooks (my dad's or my grandfather's) that I used, in addition to the assigned text, in high school.

Anything by Knuth. Seriously, one summer a professor and I just picked up copies of Concrete Mathematics and worked through large portions of it for fun. Technically I got some math credits for it, but it was really just because we wanted to. Actually, this one helped me a lot with understanding calculus. Somehow, up to that point while I knew calculus, may brain had never made the connection that integration was summation until I saw the discrete counterpart to continuous integration. I had a mechanical understanding, but no deep understanding until that moment.

There's also Calculus Made Easy[1], by Silvanus Thompson, relatively recently reprinted in an edition with additions from Martin Gardner.[2] The original edition is available in the US from Project Gutenberg, though.[3]

Quoth the 'pedia: "Calculus Made Easy is a book on infinitesimal calculus originally published in 1910 by Silvanus P. Thompson, considered a classic and elegant introduction to the subject."

[1] http://en.wikipedia.org/wiki/Calculus_Made_Easy

[2] http://www.amazon.com/Calculus-Made-Easy-Silvanus-Thompson/d...

[3] http://www.gutenberg.org/ebooks/33283

> Calculus Made Easy

Thompson wrote the original edition a century ago. It is now Public Domain.

http://www.gutenberg.org/ebooks/33283

Gardner's revised edition adds introductory material, a problem set, and updates the language to keep it roughly in line with what is taught now. I can't speak to the differences between modern editions, but I have this one:

http://www.amazon.com/Calculus-Made-Easy-Silvanus-Thompson/d...

> linear algebra

To be honest, all abstract algebra is tough on new-comers. Compared to undergraduate calculus, the "aha" moments have more pay-off, but usually take a lot more time. The significance and power of vector spaces is just not something that is easily learnt, other than by working through problems with pen-and-paper math, and while doing so, constantly asking yourself "why do mathematicians do things this way, rather than some other way?"

I bought a copy of Gilbert Strang's Linear Algebra And It's Applications when I was an undergrad, and still refer to it now. It's brilliant, but it's a traditional text book, and definitely not a "primer".

It's not the type of maths you would call "hard" (integral calculus can be infuriatingly "hard") but it's the type that takes time and work to understand. Once you understand vector spaces, QM is surprisingly straight-forward.