I took a version of this class (called The Art of Approximation) with Dr. Mahajan when he was a visiting professor at Olin College. The course helped me become fearless about tackling a broad range of math problems I knew little about, and has helped me in countless real life situations from financial planning to major work decisions.<p>Also, it's a great intro on good ways to nail PM interviews, at least at Google (where I now work, thanks in no small part to the lessons from this class).<p>If you have a spare few hours, read this book or take his classes on edX. It'll absolutely change your intuition for numbers.
An earlier book from the same author: <a href="https://mitpress.mit.edu/books/street-fighting-mathematics" rel="nofollow">https://mitpress.mit.edu/books/street-fighting-mathematics</a>
I went to graduate school at Caltech; my time there intersected with SM for about a year, but I only learned about that when he had already graduated.<p>In one of the rooms in the physics building (E. Bridge), there used to be a few shelves with old theses. While checking them out one day (probably trying to kill time before a seminar), I came across Sanjoy's thesis. It was a curious little thing, unlike any of the other theses I had seen---a bit of a hybrid between a PhD thesis and a textbook, and remarkably, very readable.<p>That thesis was, apparently, the first version of his now famous book, Street-Fighting Mathematics. After getting lost in it for a while, I went and asked the administrative assistant if I could get a copy, and she said nobody cares about those volumes on the shelves, and I could just take it if I wanted. I still have that copy with me.<p>One year I attempted to audit the (somewhat legendary) class that the book part of SM's thesis was based on---"Order of magnitude physics", taught by P. Goldreich and S. Phinney. Unfortunately, the lectures were in the morning, and I managed to wake up early enough only a few times, and dropped out afterwards.<p>I continued to collect material on related topics over the years, and am still hoping to use them some day in a course, together with SM's books.