During the last 40 years, an increasing number of commercial arithmetic and algebra texts from the period 1300-1600 has been studied. Considering the great economic development of many Italian cities during this period, it is hardly surprising that most of these texts were composed in Italy.

Francesc Santcliment’s Summa de l’art d’Aritmètica is a book on commercial arithmetic that was written in Catalan and published in 1482 in Barcelona. It was the first mathematics book printed in the Iberian Peninsula and the second printed commercial arithmetic in Europe. However, even when printed treatises like this started to be published and to be widely used, manuscripts continued
to play an essential role in the teaching of commercial arithmetic and algebra. In fact, some of these manuscripts give us a closer view on the teacher’s daily work, showing how contents of the printed treatises were adapted to each educational context.

This talk is based on my research on Catalan manuscript sources for commercial arithmetic and algebra during the late Medieval and early Renaissance periods. I will resort to some of these manuscripts to show which contents were studied and which teaching methods were used, among
other topics.