Abu'l-Hasan al-Uqlidisi
Abu'l-Hasan al-Uqlidisi
Abu'l Hasan Ahmad ibn Ibrahim Al-Uqlidisi (Arabic: أبو الحسن أحمد بن ابراهيم الإقليدسي) was a Muslim Arab[1] mathematician, who was active in Damascus[2] and Baghdad.[3]. He wrote the earliest surviving book on the positional use of the Arabic numerals, Kitab al-Fusul fi al-Hisab al-Hindi (The Arithemetics of Al-Uqlidisi) around 952.[4] It is especially notable for its treatment of decimal fractions, and that it showed how to carry out calculations without deletions.
A. S. Saidan who studied al-Uqlidisi's mathematical treatise in detail wrote:
The most remarkable idea in this work is that of decimal fraction. Al-Uqlidisi uses decimal fractions as such, appreciates the importance of a decimal sign, and suggests a good one. Not al-Kashi (d. 1436/7) who treated decimal fractions in his "Miftah al-Hisab", but al-Uqlidisi, who lived five centuries earlier, is the first Muslim mathematician so far known to write about decimal fractions.[2]