Hindu-Arabic numerals (often less accurately called Arabic numerals or numbers) had their roots in India before 300 B.C.E. From there, the use of Indian numerals followed the more western trade routes to Spain and Northern Africa that were taken by the Arabic/Islamic peoples; this consequently resulted in the expanded use of these symbols.

One of the earliest and most common devices developed for making everyday calculations was the abacus, which was still being used in Europe as late as the 15th century.

It took several more centuries for the idea to spread to Europe. Although the Spanish used some Hindu-Arabic symbols as early as the late 900s, records of a more extensive use of these symbols occurred around 1202. Italian mathematician Leonard of Pisa (also known as Fibonacci, c. 1170-c. 1250; for more about Fibonacci, see elsewhere in this chapter, and also in “History of Mathematics” and “Mathematics throughout History”) introduced the Hindu-Arabic numbers in his book Liber Abaci (The Book of the Abacus). The acceptance of such a numbering system was difficult. For example, in some places in Italy, it was forbidden to use anything but Roman numerals. By the late 15th century, most people in Europe were still using an abacus and Roman numerals.

The 16th century was the turning point, with European traders, surveyors, bookkeepers, and merchants spreading the use of the Hindu-Arabic numerals. After all, it took longer to record data using Roman numerals than with Hindu-Arabic numbers. The advent of the printing press also helped by standardizing the way the Hindu-Arabic numbers looked. By the 18th century, the “new” numeration system was entrenched, establishing a system that dominates the way we work with and perceive numbers in the 21st century. (For more information about Hindu-Arabic and Roman numerals, see “History of Mathematics.”)