Leonardo of Pisa was an Italian mathematician who lived in the late twelfth and early thirteenth centuries. He introduced Arabic, Indian, and classical-mathematical knowledge to Europe, including the use of Arabic numerals and the zero. Although he derived a number of complex theories, he was also absorbed with practical problems such as business mathematics. He wrote on algebra and number theory, and even wrote several treatises on recreational mathematics. His work led to the abandonment of Roman numerals in the West.

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