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Mathematical Treasure: Arithmetic of Sacrobosco

Frank J. Swetz (The Pennsylvania State University)

While many details of his early life remain unclear, we do know that the mathematician Johannes de Sacrobosco (ca 1195–ca 1256) eventually became a professor of mathematics at the University of Paris. In the Algorismus, thought to be his earliest work, Sacrobosco promoted the Hindu-Arabic methods of numerical calculation and problem solving.

A portion of the Algorismus appears in a 13th-century manuscript collecting mathematical and astronomical texts from a variety of authors (Harley MS 4350). The first page of the work (folio 15v) shows a scribe writing out Hindu-Arabic numerals:

Folio 15v from a 13th century manuscript of Algorismus by Johannes de Sacrobosco

A manuscript from Paris (Harley MS 3647), circa 1292, gives a table of multiplication from Sacrobosco’s Algorismus (folio 21):

Folio 21 from an manuscript copy of Algorismus by Johannes de Sacrobosco, circa 1292

The images above were obtained through the courtesy of the British Library. Further investigation of the images and their source can be obtained through the online services of the British Library. Where possible, manuscript reference numbers are given for the item being viewed.

Index to Mathematical Treasures

Frank J. Swetz (The Pennsylvania State University), "Mathematical Treasure: Arithmetic of Sacrobosco," Convergence (January 2020)