Eastern Arabic numerals

The Eastern Arabic numerals, also called Indo-Arabic numerals, are the symbols used to represent numerical digits in conjunction with the Arabic alphabet in the countries of the Mashriq (the east of the Arab world), the Arabian Peninsula, and its variant in other countries that use the Persian numerals on the Iranian plateau and in Asia.

The early Hindu–Arabic numeral system used a variety of shapes.^[1] It is unknown when the Western Arabic numeral shapes diverged from those of Eastern Arabic numerals; it is considered that 1, 2, 3, 4, 5, and 9 are related in both versions, but 6, 7 and 8 are from different sources.^[2]

^ Kunitzsch, Paul (2003). "The Transmission of Hindu–Arabic Numerals Reconsidered". In J. P. Hogendijk; A. I. Sabra (eds.). The Enterprise of Science in Islam: New Perspectives. MIT Press. pp. 3–22. ISBN 978-0-262-19482-2. This leads to the question of the shape of the nine numerals. Still after the year 1000 al-Biruni reports that the numerals used in India had a variety of shapes and that the Arabs chose among them what appeared to them most useful. And al-Nasawi (early eleventh century) in his al-Muqni' fi l-hisåb al-hindi writes at the beginning, when describing the forms of the nine signs, "Les personnes qui se sont occupées de la science du calcul n'ont pas été d'accord sur une partie des formes de ces neuf signes; mais la plupart d'entre elles sont convenues de les former comme il suit" (then follow the common Eastern Arabic forms of the numerals). Among the early arithmetical writings that are edited al-Baghdådi mentions that for 2, 3, and 8 the Iraqis would use different forms. This seems to be corroborated by the situation in the Sijzi manuscript. Further, the Latin adaptation of al-Khwårizmi's book says that 5, 6, 7, and 8 may be written differently. If this sentence belongs to al-Khwårizmi's original text, that would be astonishing. Rather one would be inclined to assume that this is a later addition made either by Spanish-Muslim redactors of the Arabic text or by the Latin translator or one of the adapters of the Latin translation, because it is in these four signs (or rather, in three of them) that the Western Arabic numerals differ from the Eastern Arabic ones.
^ Kunitzsch, Paul (2003). "The Transmission of Hindu–Arabic Numerals Reconsidered". In J. P. Hogendijk; A. I. Sabra (eds.). The Enterprise of Science in Islam: New Perspectives. MIT Press. pp. 3–22. ISBN 978-0-262-19482-2. That the Eastern Arabic numerals were also known in al-Andalus is demonstrated by several Latin manuscripts that clearly show the Eastern forms… Unfortunately, the documentary evidence on the side of Western Arabic numerals is extremely poor. So far, the oldest specimen of Western Arabic numerals that became known to me occurs in an anonymous treatise on automatic water-wheels and similar devices in MS Florence… dated to 1265 and 1266… Here we have the symbols for 1, 2, 3, 4, 5, 8, and 9. The figures for 2 and 3 look like the corresponding Eastern Arabic forms and are not turned by 90o as in other, more recent, Maghrebi documents… When one compares the Eastern and the Western Arabic forms of the numerals, one finds that they are not completely different. The Western forms of 1, 2, 3, 4, 5, and 9 can be recognized as being related to, or derived from, the corresponding Eastern forms. Major difficulty arises with 6, 7, and 8. It may not be accidental that the oldest existing Latin re-working made from the translation of al-Khwårizmi's Arithmetic mentions just these three figures (plus 5) as being differently written. As I have already said earlier, this notice can hardly stem from al-Khwårizmi himself; rather it may have been added by a Spanish-Arabic redactor of al-Khwårizmi's text. He would have been best equipped to recognize this difference. The Latin translator, or Latin adapters, would less probably have been able to notice the difference between the Eastern and Western Arabic forms of these four numerals. We cannot explain why, and how, the three Western figures were formed, especially since we have no written specimens of Western Arabic numerals before the thirteenth century.

[1] Kunitzsch, Paul (2003). "The Transmission of Hindu–Arabic Numerals Reconsidered". In J. P. Hogendijk; A. I. Sabra (eds.). The Enterprise of Science in Islam: New Perspectives. MIT Press. pp. 3–22. ISBN 978-0-262-19482-2. This leads to the question of the shape of the nine numerals. Still after the year 1000 al-Biruni reports that the numerals used in India had a variety of shapes and that the Arabs chose among them what appeared to them most useful. And al-Nasawi (early eleventh century) in his al-Muqni' fi l-hisåb al-hindi writes at the beginning, when describing the forms of the nine signs, "Les personnes qui se sont occupées de la science du calcul n'ont pas été d'accord sur une partie des formes de ces neuf signes; mais la plupart d'entre elles sont convenues de les former comme il suit" (then follow the common Eastern Arabic forms of the numerals). Among the early arithmetical writings that are edited al-Baghdådi mentions that for 2, 3, and 8 the Iraqis would use different forms. This seems to be corroborated by the situation in the Sijzi manuscript. Further, the Latin adaptation of al-Khwårizmi's book says that 5, 6, 7, and 8 may be written differently. If this sentence belongs to al-Khwårizmi's original text, that would be astonishing. Rather one would be inclined to assume that this is a later addition made either by Spanish-Muslim redactors of the Arabic text or by the Latin translator or one of the adapters of the Latin translation, because it is in these four signs (or rather, in three of them) that the Western Arabic numerals differ from the Eastern Arabic ones.

[2] Kunitzsch, Paul (2003). "The Transmission of Hindu–Arabic Numerals Reconsidered". In J. P. Hogendijk; A. I. Sabra (eds.). The Enterprise of Science in Islam: New Perspectives. MIT Press. pp. 3–22. ISBN 978-0-262-19482-2. That the Eastern Arabic numerals were also known in al-Andalus is demonstrated by several Latin manuscripts that clearly show the Eastern forms… Unfortunately, the documentary evidence on the side of Western Arabic numerals is extremely poor. So far, the oldest specimen of Western Arabic numerals that became known to me occurs in an anonymous treatise on automatic water-wheels and similar devices in MS Florence… dated to 1265 and 1266… Here we have the symbols for 1, 2, 3, 4, 5, 8, and 9. The figures for 2 and 3 look like the corresponding Eastern Arabic forms and are not turned by 90o as in other, more recent, Maghrebi documents… When one compares the Eastern and the Western Arabic forms of the numerals, one finds that they are not completely different. The Western forms of 1, 2, 3, 4, 5, and 9 can be recognized as being related to, or derived from, the corresponding Eastern forms. Major difficulty arises with 6, 7, and 8. It may not be accidental that the oldest existing Latin re-working made from the translation of al-Khwårizmi's Arithmetic mentions just these three figures (plus 5) as being differently written. As I have already said earlier, this notice can hardly stem from al-Khwårizmi himself; rather it may have been added by a Spanish-Arabic redactor of al-Khwårizmi's text. He would have been best equipped to recognize this difference. The Latin translator, or Latin adapters, would less probably have been able to notice the difference between the Eastern and Western Arabic forms of these four numerals. We cannot explain why, and how, the three Western figures were formed, especially since we have no written specimens of Western Arabic numerals before the thirteenth century.

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