A more substantial printed book in the vernacular abbacus tradition was the scholarly work Summa de arithmetica, geometric, proportions et proportionalità, written by the mathematician Luca Pacioli just a few years later, in 1494. A significant difference between Pacioli’s book and Treviso Arithmetic is that Pacioli dealt with negative numbers. The concept of negative numbers was new in Europe, and Pacioli is believed to have provided the first printed explanation.