I'm not exactly sure what level of math you're really looking for. But something I think could be useful is to go check out your local college's textbooks. At least at the UW, most of the 100-level calculus,etc classes use off-campus printing that consequently costs about $5.00 for a more-or-less educational book with exercises and problem sets. I know this because I had to take the class, but for learning about it outside of a classroom it would still be a good deal.

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- Remnant
- (Steve Schmitt)