Transmission of the Arabic Numeral System

Timeline

1. 1161–1165Baghdad and Damascus · Islamic worldIn the 1160s, merchants, astronomers, and judges in the Islamic world routinely used Indo-Arabic numerals for accounts, star tables, and inheritance calculations. The concepts of positional notation and zero were already embedded in arithmetic textbooks and practical tables, forming a mature transmission network continuous since the Baghdad era.
2. 1166–1170Toledo and Sicily · Iberia and SicilyIn the late 1160s, translators such as Gerard of Cremona rendered Arabic mathematical works into Latin at Toledo, and the Indo-Arabic numeral symbols entered the preparatory circles of European universities along with the texts. Commercial reckoning masters in Sicily and southern Italy also mixed Arabic and Roman numerals in trade documents, slowly pushing the symbol system northward into northern Europe.