Raffaele Danna, "The Craft of Indo-Arabic Numerals: How Practical Arithmetic Shaped Commerce and Mathematics in Western Europe, 1200–1600" (Harvard UP, 2026)

About this episode

Dr. Raffaele Danna discusses the transition from Roman to Indo-Arabic numerals in Europe and its impact on commerce and mathematics from 1200 to 1600.

In the thirteenth-century Mediterranean, commerce transformed as merchants shifted from Roman to Indo-Arabic numerals—an alternative that better facilitated complex calculations. It has long been known that this transition stemmed from Europe’s increasing exchanges with India, Persia, and the Arabic world. Yet much remains to be understood about how Indo-Arabic numerals—and the practical arithmetic they enabled—actually spread across Europe. As Dr. Raffaele Danna shows in The Craft of Indo-Arabic Numerals: How Practical Arithmetic Shaped Commerce and Mathematics in Western Europe, 1200–1600 (Harvard University Press, 2026), it was hundreds of ordinary merchants, schoolmasters, and artisans who nurtured these changes, thereby driving key advances in both commerce and mathematics. Drawing on an original catalog of more than 1,200 practical arithmetic manuals, Dr. Danna charts the incremental spread of the new figures with unprecedented precision. While Italian merchants were the early adopters, it took nearly three centuries for Indo-Arabic numerals to become established in northern Europe. As Dr. Danna shows, adoption did not follow the routes of maritime trade. Rather…

People in this episode

Host: Marshall Poe

Guest: Raffaele Danna

Topics covered

• Indo-Arabic numerals
• commerce
• mathematics
• historical arithmetic
• European history
• merchant practices

Keywords

• Indo-Arabic numerals
• commerce
• mathematics
• arithmetic manuals
• European history
• merchant practices
• numerical systems

Mentioned in this episode

Organizations: Harvard University Press

Books & works: The Craft of Indo-Arabic Numerals: How Practical Arithmetic Shaped Commerce and Mathematics in Western Europe, 1200–1600

Places: Europe, Italy, Persia, India

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