Since the early 14th century, Florence had been one of the cities most active in disseminating mathematical culture. The city’s mercantile tradition had favored such acceptance of the new system of calculation introduced to the Western World by Arab mathematicians that, in 1343, there were six abacus schools teaching over a thousand pupils. In these schools, Indo-Arabic arithmetic was taught along with Euclidean geometry, according to the method of Leonardo Fibonacci (1170-1250). It is probable that the practical geometry of the abacus schools gave rise to the rules that, in the early 15th century, sanctioned the birth of linear perspective, the new method of representation destined to revolutionize the development of the figurative arts in the Renaissance. Artists and mathematicians pooled their knowledge to establish the rules that laid the Euclidean foundations of the new pictorial language. The new method of representation was then to undergo extraordinary development in the cartographic and topographic-military fields as well.