If you have a keen interest in either mathematics or history, perhaps both, Gaurav Tekriwal’s new book is right up your alley. Titled 'The Great Indian Mathematicians: 15 Pioneers Who Put Indian Mathematics on the World Map', it has been published by Puffin Books. Apart from being an educator and author, Tekriwal is also the founder and president of the Vedic Maths Forum India. This should explain his tremendous passion for the subject that he writes about. I did not grow up enjoying mathematics, so I am always a bit puzzled when people wax eloquent about how fascinated they are by this subject, its real-life applications, and its connections to philosophy and aesthetics. I guess a good teacher in one’s early years makes a huge difference and helps cultivate an appreciation for mathematics and its mysteries. Tekriwal’s book called out to me because it looks at Indian history from a unique vantage point — the contributions of Indian mathematicians spread out over 5000 years. Antra K’s sketch of ace mathematician Shakuntala Devi on the book’s front cover reminded me of Anu Menon’s wonderful biopic Shakuntala Devi (2020) starring Vidya Balan. Therefore, I decided to plunge in, and learn about some of the other geniuses who came before her and after. “We, as a nation, were colonized for over 200 years and our perception of the history of Indian maths and mathematicians was distorted and corrupted. We started losing faith in our own culture and heritage and started looking at things from a Western standpoint,” writes Tekriwal in his introduction to this book. He adds, “Many concepts that were widely believed to have originated from the English-speaking world were discovered in India.” If this sounds like a tall claim, you might want to take a look at the bibliography towards the end of the book. It offers a chapter-wise list of sources that the author has drawn on while researching and writing. The list includes books, newspaper reports, YouTube videos, and websites. Some of the chapters also contain QR codes that readers can scan if they want to access supplementary audio-visual resources and enrich their understanding of concepts. After reading Tekriwal’s book, I am excited to watch The Story of Maths (2008) — a television series narrated by mathematics professor Marcus Du Sautoy — apart from Matt Brown’s film The Man Who Knew Infinity (2015) featuring Dev Patel, and Vikas Bahl’s film Super 30 (2019) with Hrithik Roshan. Tekriwal recommends these resources to get acquainted with three outstanding mathematicians from India — Madhava, Srinivasa Ramanujan, and Anand Kumar. Madhava, who was also an astronomer, laid the foundation for the Kerala School of Mathematics that flourished between the late 14th century and the 18th century. Tekriwal writes, “He made groundbreaking discoveries by moving away from the traditional finite processes of algebra to infinity with its implications on the future development of calculus — a vital tool for measuring time, making almanacs and finding directions at sea.” Tekriwal tells the story behind the so-called Hardy-Ramanujan number and the collaboration between this Indian mathematician and his British mentor GH Hardy at Cambridge University. Ramanujan achieved a lot in his short life. He was 32 when he died. To honour him and continue his legacy, the International Centre for Theoretical Physics (ICPT) in Italy has instituted the ICTP Ramanujan Prize for Young Mathematicians from Developing Countries. Tekriwal also makes a brief mention of the Ramanujan Museum in Chennai, which I knew nothing of until I read this book. It is located in the premises of the Avvai Cultural Academy in Royapuram, where the mathematician’s photographs, memorabilia and correspondence are preserved for the benefit of people interested in learning about his stellar achievements. I hope to visit this place of historical importance the next time I make a trip to Chennai. Anand Kumar from Patna, who is an internationally renowned mathematics educator, runs the Ramanujan School of Mathematics. He is best known for initiating the Super 30 programme that provides high-quality and free coaching to “students from economically impoverished sections” for the Indian Institute of Technology-Joint Entrance Examination (IIT-JEE). They are also provided with food, lodging and study material for a whole year. The most intriguing chapter in Tekriwal’s book is the one about the Indus Valley Civilization. He writes, “If you were at the site of the Indus Valley excavation, you would find that the city roads intersect with each other perpendicularly (at right angles) like a grid. The houses were made with bricks that maintained the ratio of 4:2:1 for the length, width and height…there was a standard system of weights and measures in place in the entire civilization.” While going through this book, it is important to remember that territorial boundaries and political realities have changed a lot between 3000 BCE and today. The Indus Valley Civilization, for instance, is a shared heritage of India, Pakistan and Afghanistan, because it stretched over a large landmass that is now divided into different nation-states. Tekriwal discusses the decimal ruler found by archaeologists in detail. It is also known as the Mohenjo-Daro ruler because of the place where it was discovered. He writes, “This ruler was divided into units corresponding to 1.32 inches and these markings are done with amazing accuracy to within 0.005 of an inch. This length has thus been named the Indus inch.” In this book, you will get to exercise your mental muscles by solving various mathematical problems and also meet mathematicians such as Baudhayana, Pingala, Aryabhata, Brahmagupta, Varahamihira, Bhaskaracharya, Narayana Pandita, Sridharacharya, Mahaviracharya, Swami Bharati Krishna Tirthaji, Manjul Bhargava, among others. All of them have contributed richly not only to the history of mathematics but to the history of India. I wondered why Shakuntala Devi, called “the human computer”, is the only woman in the book. Surprisingly, there is no mention of Anita Rampal and Parvin Sinclair, who are accomplished scholars and math educators. They have been associated with India’s National Council of Educational Research and Training and other academic institutions. If Tekriwal addresses these gaps in the next edition, that would be a welcome addition to a fine book.