The Man of Numbers

May 15, 2011

Three cheers for Leonardo Pisano, nicknamed Fibonacci, heralded by NPR's "Math Guy" Devlin (Mathematics Education for a New Era: Video Games as a Medium for Learning, 2011, etc.) as the man who introduced Hindu-Arabic numbers (0 to 9) and rules of arithmetic to Europe in the 13th century.

The author writes that by far the most important contribution that Pisano native made to Western culture was not the Fibonacci numbers (the series in which each term is the sum of the two previous terms, e.g., 1,1,2,3,5,8,13—celebrated in The Da Vinci Code) but the replacement of Roman numerals with the familiar 10 digits and place notation. That was a boon to merchants and bankers, moneychangers and tax collectors, just when the world was poised for the science and technology discoveries of the Renaissance. It all came about because Pisano's father, a customs official, took his teenage son with him to North Africa, where the boy learned about the numerical system that Arab traders had brought from India. Devlin makes clear that he was not a passive transmitter of new knowledge but a gifted thinker whose magisterial Liber Abaci (Book of Calculation), published in 1202, and later popularizations, as well as works in algebra and geometry, mark him as one of mathematics' great minds. As for the series, Pisano wrote that it was known early on to Indian scholars, and he stated it as a problem to determine how many rabbits a fertile pair would produce in a year "when it is the nature of them in a single month to bear another pair. And in the second month those born to bear also."

A wonderful book for history-of-science buffs that will also amuse math teachers, because the many problems and solutions included are simply medieval versions of the word problems that are the bane of many high-school students.

(COPYRIGHT (2011) KIRKUS REVIEWS/NIELSEN BUSINESS MEDIA, INC. ALL RIGHTS RESERVED.)

July 1, 2011

Devlin, noted mathematician (Stanford Univ.) and author of more than 30 books (The Language of Mathematics The Math Gene), tells the fascinating story of Fibonacci's mathematical and cultural legacy. Leonardo of Pisa (1170-1240), called Fibonacci by a historian many centuries after his life, was inspired by the newly merging influences of Indian, Hindu-Arabic, and Western number systems. He not only introduced to the West the number sequence 0, 1, 1, 2, 3, 5, 8, 13..., whereby each number is the sum of the two that precede it, but helped shape the development of modern mathematics and commerce. In an entertaining style, Devlin explains the influence of Liber Abbaci (Book of Calculation), Fibonacci's 600-page work published in manuscript form in 1202. This tome helped make mathematics accessible to 13th-century Italian businessmen and other ordinary people. Fibonacci's introduction to commerce of the digits 0 through 9 prepared the stage for the development of modern symbolic algebra and hence modern mathematics. Devlin writes for a general audience, effectively introducing and explaining basic mathematical concepts, and includes scholarly notes and references. VERDICT A must-read for anyone interested in the history of math, including undergraduates, mathematicians, and amateur historians.--Ian D. Gordon, Brock Univ. Lib., St. Catharines, Ont.

Copyright 2011 Library Journal, LLC Used with permission.

Starred review from June 1, 2011
When the smoke cleared after a month-long battle in 1945 between German and American armies struggling for control of Camposanto, Italians discovered that the cannonades had spared one of the city's most beloved landmarks, a statue of Leonardo of Pisa, often called Fibonacci. In telling the story of this miraculously preserved statue, Devlin illuminates one of the most remarkable and underappreciated episodes in cultural history. Often remembered only for the Fibonacci series of numbers generated by a deceptively simply problem about breeding rabbits, Leonardo actually deserves credit for transforming Western society by giving scholars and merchants a potent new tool for counting and calculating. By introducing Hindu-Arabic arithmetic, he freed the West from its bondage to Roman numerals so cumbersome that they made even multiplication an arduous task. Remarkably lucid and comprehensive, Leonardo's Liber abbaci (Book of calculation) excited intellectuals with the conceptual power of the Hindu zero and the subtle sophistication of Arabic algebra while also empowering practical traders and builders. Though no one knows much about Leonardo's personal life, Devlin tells readers plenty about the European and North African world that incubated a daring new mathematics, thus quickening the pace of the Renaissance. A surprising visit to a forgotten well-spring of modern thought.(Reprinted with permission of Booklist, copyright 2011, American Library Association.)