Fibonacci

Lore & Background

He travelled with his father as a young boy and was educated in Bugia, where he learned about the Hindu–Arabic numeral system. Fibonacci travelled around the Mediterranean coast, meeting merchants and learning their arithmetic systems, and soon realized the advantages of the Hindu–Arabic system over Roman numerals. The book introduced the modus Indorum (method of the Indians) with ten digits including a zero and positional notation, and applied it to commercial bookkeeping, converting weights and measures, calculating interest, and money-changing. Fibonacci was a guest of Emperor Frederick II, and a member of the court, John of Palermo, posed several mathematical problems for him to solve.

Reader's Guide

Fibonacci's Liber Abaci had a profound influence on European thought by replacing Roman numerals and the abacus with the Hindu–Arabic numeral system, making business calculations easier and faster and assisting the growth of banking and accounting. The book also posed a rabbit population problem whose solution produced the Fibonacci sequence, where each number is the sum of the previous two. Although Indian mathematicians had described the sequence earlier, Fibonacci's work introduced it to Europe. His legacy includes the Brahmagupta–Fibonacci identity, the Fibonacci search technique, and the Pisano period.

Did You Know?

• The Fibonacci sequence had been described by Indian mathematicians as early as the sixth century, before Fibonacci's Liber Abaci.