The introduction of Arabic (Hindu-Arabic, actually) numerals into the medieval West was not a mechanical process. Apart from translations of Arabic works on arithmetic and the copying and reproducing of numerals as found in the Arabic sources, European scholars, especially those working in Toledo, turned their minds to more philosophical aspects of these numbers. One was the meaning behind the name of Arabic numerals.
The earliest specifically Arabic numerals are those of the so-called ‘abjad’ model, a decimal numeral system in which the 28 letters of the Arabic alphabet are assigned numerical values. ‘Abjad’ refers to the first letters in the Arabic alphabet. The abjad numerals were later replaced in the Arabic-speaking world with Hindu numerals. From the 10th century onwards, Europeans began reaping the harvest of a numerical system feeding on both Arabic (Abjad) and Indian (al-‘Adad al-Hindi) numerals – which came to be known as Arabic.
For European scribes unaccustomed to writing non-Latin script, this was not easy. Gerbert d’Aurillac, future Pope Sylvester II (999-1003 AD) and one of the leading scientific minds of the time, discussed the meaning of Arabic numeral names in his mathematical works. In one of the manuscripts containing these texts, a scribe tried to write Arabic letters corresponding to their Latin transliteration but gave up after seven words. The letters are on the middle band (in 12 to about 1 o’clock position) of the wheel below – the representation of an astrolabe.