This is an interesting read for math educators. This book takes twenty concepts studied in elementary and high school mathematics, and demonstrates different ways the concept could be approached. Many of them are familiar approaches that most educators will have seen before; some are obscure and work only in specific situations. While I have my preferred ways, I found the alternate pathways helped me gain a deeper understanding of the concept and to see the pros and cons of my preferred methods. I appreciated the commentary that the author provides after demonstrating each method.
I've been trying to get my students to also understand there is no single 'correct' way to approach a problem. While it would be overwhelming for students to learn seven different ways to subtract, the alternate methods presented in the book would be helpful in two ways. If a student is having trouble understanding a more conventional approach, perhaps one of the alternates (e.g., something more visual) would be helpful. Secondly, for students who have caught onto a conventional approach quickly, presenting an alternate approach helps them gain a multi-dimensional and deeper understanding of the concept.