This article gives an outline of teaching patterns and mercantile handbooks, which constituded the educational basis for Milanese merchants and financiers during the Spanish Era. After tracing out a map of commercial arithmetic schools in Milan, the paper takes into account the teaching contents, thanks to the perusal of manuals and treatises used in the city at that time. A clear problem-based learning approach emerges. The theorethical degree is reduced while major emphasis is devoted to the practice and the moral construction of young businessmen. Rhymes are used to memorize calculation rules, arithmetic games to learn principles while drawings are adopted to give practical examples. Starting from the first decades of the 17th century, the initial linkage to the Genoese merchant education faded away and the local training system became fully autonomous, getting more strenght from the interplay with the florishing life of Milanese economy. Trade and financial knowlegde and skills, along with the rethinking of the use of money, helped settle a conceptual and operative framework where commerce and finance rooted concrete institutions, instruments and innovations enabling higher yields and enhancing the overall development of such activities.
Keywords: Merchants Education, Commercial Arithmetic, Economic Thought, Early Modern Age, Milan, Spanish Period, Sixteenth-Sevententh Centuries.