October 18 update:
Yash Chandak was interviewed today for a story about his mental math book. The story will air on Friday, October 20, 2017 on CW33 at 5:00pm. After the story airs it can be found on CW33.com.
A Repertoire of Number Sense Techniques
By Yash Chandak, 2017
Yash said that he wrote this book for all those that can benefit - from the beginner who is just reading a poster asking them to join the school's Number Sense team - to the seasoned competitor eyeing State medals. He hopes this book serves as a guide and as inspiration, to not only pique interest but be that on which a competitor can build a foundation. In this book, you'll find a step-by-step guide on how-to solve Number Sense problems and prepare you for any mental math competitions. Over 80 mental math techniques are explained, and there are over 750 problems to learn, train, and improve with.
Secondly, Yash wrote this book because through his years competing in Number Sense, he noticed the lack of a reliable, all-inclusive resource for top level competitors. Basically, he would have to hunt for each individual trick or would have to prove them himself. Because of this, he combined all the tricks he finds necessary for any competitor of middle or high school to know. He also included the proof of the trick so that if the reader ever encounters a problem they don't know the answer to, and there is not a solution to it in the book, they can see how Yash proved tricks to hopefully get a sense for how to derive a new trick.
Third, Yash wrote the book to leave a lasting legacy at SEM. The underclassmen often asked Yash number sense questions. Next year, he won't be avaiable to assist when he's in college and he doesn't want his nine years of experience to be wasted, so he wrote this book as his contribution to the competition.
When asked about collaboration, he responded that his process was well very isolated. His math professior, Mr. Newton, didn't know about it until he was about halfway in; but insists that does not diminish Mr. Newton's contributions. Mr. Newton has countless resources of tricks and sets of tests Yash pulled and adapted content from in the book.
When asked why he didn't sell the book, Yash answered that he wrote the book as a service to his teammates and as an obligation he felt - being their team captain. He never intended for his work to be monetized. Since he has shared the free download link with his teammates, he has also shared it with many schools inside and outside of DISD. Yash feels like the writing will do its purpose and improve the competition scores of others.
I think we can all be proud of Yash and agree indeed that he has left his legacy at SEM!