Find number abcIf 29ca3 + 29ba3 = a880c find number abc. Multiple solutions may exist.
Correct answers: 57
The first user who solved this task is On On Lunarbasil.
First dated printed arithmetic bookIn 1478, the anonymous Arte dell'Abbaco(“The Art of the Abacus”), printed in Treviso, Italy had this publication date. It is the first dated printed book on arithmetic. The unknown author was likely a priest, and it was dedicated to some of his young friends who kept asking for it. The printer was probably Geradus de Lisa, dé Flandria. The 124-page text dealt with commercial applications of arithmetic, so the language was the local vernacular Venetian dialect, not the scholarly Latin used for the abstract studies of universities. The book teaches the four main operations, with numerous examples, and the concept of fractions (but not the as yet unknown decimals). He shows how to calculate the date of the new Moon. Although some pamphlets on Algorithmus are possibly older than this book, they are undated.«[Image: detail of a calculation shown in the book.]