This book examines a Tractatus algorismi written in 1307 in Montpellier by Jacopo da Firenze. It is one of the earliest surviving "abbacus" treatises and the first to contain a presentation of algebra. This current book includes the text in late medieval Italian with an English translation. The author offers extensive discussions of the contents and its place within early abbacus culture. Historians, mathematicians, and students interested in the history of mathematics will find this text provides a fascinating glimpse into the field’s early development and evolution.