Luca Pacioli's contribution

Luca Pacioli, a Franciscan friar, is generally associated with the introduction of double entry bookkeeping. In 1494 he published his book, Summa de Arithmetica.  In Summa Arithmetica, Pacioli introduced symbols for plus and minus for the first time in a printed book, symbols that became standard notation in Italian Renaissance mathematics. Summa Arithmetica was also the first known book printed in Italy to contain algebra. Although Luca Pacioli did not invent double-entry bookkeeping, his 27-page treatise on bookkeeping contained the first known published work on that topic, and is said to have laid the foundation for double-entry bookkeeping as it is practiced today. Even though Pacioli's treatise exhibits almost no originality, it is generally considered as an important work, mainly because of its wide circulation, it was written in the vernacular Italian language, and it was a printed book.

According to Pacioli, accounting is an ad hoc ordering system devised by the merchant. Its regular use provides the merchant with continued information about his business, and allows him to evaluate how things are going and to act accordingly. Pacioli recommends the Venetian method of double-entry bookkeeping above all others. Three major books of account are at the direct basis of this system: the memoriale (Italian:memorandum), the giornale (Journal), and the quaderno (ledger). The ledger is considered as the central one and is accompanied by an alphabetical index.

Pacioli's treatise gave instructions in how to record barter transactions and transactions in a variety of currencies – both being far more commonplace than they are today. It also enabled merchants to audit their own books and to ensure that the entries in the accounting records made by their bookkeepers complied with the method he described. Without such a system, all merchants who did not maintain their own records were at greater risk of theft by their employees and agents: it is not by accident that the first and last items described in his treatise concern maintenance of an accurate inventory

www.wikipedia.com