These schools probably first appeared during the thirteenth century, stimulated by the publication and widespread distribution of a textbook by Leonardo Fibonacci. Also known as Leonardo of Pisa, he was one of the greatest number theorists in the history of mathematics. But he had even greater impact on early capitalism. When his Liber Abaci (Book of the Abacus) appeared in 1202, it made Hindu-Arabic numerals and the concept of zero available for the first time outside the circle of professional mathematicians.
