In 1202, a 32-year old Italian finished one of the most influential books of all time, which introduced modern arithmetic to Western Europe. Devised in India in the 7th and 8th centuries and brought to North Africa by Muslim traders, the Hindu-Arabic system helped transform the West into the dominant force in science, technology, and commerce, leaving behind Muslim cultures which had long known it but had failed to see its potential. The young Italian, Leonardo of Pisa (better known today as Fibonacci), had learned the Hindu number system when he traveled to North Africa. The book he created was Liber abbaci, the “Book of Calculation,” and its publication led directly to large-scale international commerce and the scientific revolution of the Renaissance. Now in The Man of Numbers: Fibonacci’s Arithmetic Revolution, NPR’s “Math Guy” and one of the great math popularizers of our time, Keith Devlin, recreates the life and enduring legacy of an overlooked genius, and in the process makes clear how central numbers and mathematics are to our daily lives. (Walker & Company/Bloomsbury)