The Art and Craft of Problem Solving https://archive.org/details/the-art-and-craft-of-problem-solving https://archive.org/details/the-art-and-craft-of-problem-s

The Art and Craft of Problem Solving https://archive.org/details/the-art-and-craft-of-problem-solving https://archive.org/details/the-art-and-craft-of-problem-sol... This is only math book I've ever read that teaches the mindset needed to work mathematics problems, rather than mathematical concepts or techniques.