The author of this mathematical treatise, Bahā' al-Dīn Al-‘Amilī (1547–1621), is considered one of the leading intellectuals of 17th-century Safavid Persia (present-day Iran). He was born in Baalbek (present-day Lebanon) but moved to Persia in his youth where he devoted his entire life to study. He excelled in various fields, leaving a legacy of more than 80 books on a wide variety of subjects that included theology and mysticism, astronomy, mathematics, poetry, and architecture. He wrote in both Persian and Arabic. He was the teacher of Mulla Sadra, one of the leading intellectuals of the Persian philosophical renaissance and a figure in the Illuminationist movement, an original philosophical school that tried to harmonize Medieval Islamic philosophy, mysticism, and Shiite Islam. Al-‘Amilī’s contribution in the field of architecture is still visible in the city of Isfahan, where he designed Imam Square and the homonymous mosque and worked on a system of artificial channels to divert the course of the Zayandeh River. This treatise, a compendium of mathematics, and the astronomical treatise Fī Tasrīh al-Aflāk (The anatomy of the heavens), are two of Bahā' al-Dīn’s few works in Arabic. The ten chapters of the work offer a summary of arithmetical and algebraic operations. The author alternates prose passages with explanatory numerical tables. The presence of many interlinear notes and marginalia indicate that the manuscript was actually used for study and was not just a decorative object.