Hindu-Arabic numerals

I think we call them Arabic more often because we got them through the Arabs. The Persian mathematician Abu Abdullah Muhammad bin Musa al-Khwarizmi (whence our words algoreism and algorithm) was the first to describe the numbering system in his book on algebra, Hisab al-jabr wa al-muqabala, in ca.820 CE. The book was translated in Latin and was a big hit into the Middle Ages.

http://en.wikipedia.org/wiki/Khwarizmi