Luca Pacioli

Luca Pacioli published the first printed description of double-entry bookkeeping and is called the father of accounting. Born in Sansepolcro in Tuscany around 1447, he was educated partly by the painter Piero della Francesca, a fellow townsman, and worked as a tutor to a Venetian merchant's sons, learning commercial arithmetic in the place where it was most advanced. He became a Franciscan friar around 1470 and taught mathematics at universities across Italy — Perugia, Naples, Rome, Milan, Florence and Bologna. In 1494 he published Summa de arithmetica, geometria, proportioni et proportionalita in Venice, one of the first mathematical books printed. It is a compendium of everything then known of arithmetic, algebra and commercial mathematics, written in Italian rather than Latin so that merchants could use it. Twenty-seven pages of it describe the method of Venice: the memorandum, journal and ledger; debits on the left and credits on the right; every transaction entered twice; and the requirement that the books balance and be closed before sleeping. He did not invent the system, which Italian merchants had used for two centuries, but printing it made it universal. He moved to Milan in 1496 to teach at Ludovico Sforza's court, where he lived and worked with Leonardo da Vinci. Leonardo drew the sixty polyhedra for Pacioli's Divina proportione, completed in 1498 and printed in 1509, a treatise on the golden ratio; Pacioli in turn taught Leonardo mathematics and perspective. He also wrote on chess and collected mathematical puzzles, and translated Euclid. He died in Sansepolcro around 1517.

• Lived: 1447 CE – 1517 CE
• Nationality: Italian
• Roles: mathematician, friar, writer