Born around 1170 into the Bonacci family of Pisa, Leonardo of Pisa was the son of the prosperous merchant Guglielmo, who sought to have his son follow in his footsteps. Therefore, when Guglielmo was appointed the customs collector for the Algerian city of Bugia (now Bejaia), around 1190, he brought Leonardo with him. It was here that the young man studied with a Muslim schoolmaster who introduced him to the Hindu-Arabic system of enumeration along with Hindu-Arabic methods of computation. Then, as he continued his life in the mercantile business, Leonardo found himself traveling to Constantinople, Egypt, France, Greece, Rome, and Syria, where he continued to investigate the various arithmetic systems then being used. Consequently, upon returning home to Pisa around 1200, Leonardo found himself an advocate of the elegant simplicity and practical advantage of the Hindu-Arabic number system—especially, when compared with the Roman numeral system then being used in Italy. As a result, by the time of his death in about 1240, Italian merchants started to recognize the value of the Hindu-Arabic number system and gradually began to use it for business transactions. By the end of the sixteenth century, most of Europe had adjusted to the system.
In 1202, Leonardo published his pioneering masterpiece, the Liber Abaci (The Book of Calculation or The Book of the Abacus). Therein he introduced the Hindu-Arabic number system and arithmetic algorithms to the continent ...