Leonardo Pisano, an Italian mathematician also known as Leonardo of Pisa or Leonardo Fibonacci, is instrumental in reviving ancient mathematics.

Assembling bits of arithmetic and algebra that he has accumulated during his travels, he makes significant contributions of his own, including his 1202 treatise on arithmetic and elementary algebra, Liber abbaci (“Book of the Abacus”).

In this, he introduces to the Latin West both the modern Hindu-Arabic system of numerals using ten symbols, and the Arabic place-valued decimal system.