# Person: Al-Uqlidisi, Abu&amp;amp;#x27;l Hasan Ahmad ibn Ibrahim

Al-Uqlidisi was an Islamic mathematician who wrote two works on arithmetic. He may have anticipated the invention of decimals.

### Mathematical Profile (Excerpt):

• The manuscript gives al-Uqlidisi's full name on the front page as well as the information that he composed the text in Damascus in 952-53.
• In the introduction al-Uqlidisi writes that he travelled widely and learnt from all the mathematicians he met on his travels.
• Other than being able to deduce a little of al-Uqlidisi's character from his writing, we have no other information on his life.
• The Kitab al-fusul fi al-hisab al-Hindi of al-Uqlidisi is the earliest surviving book that presents the Hindu system.
• There is plenty of evidence here that al-Uqlidisi must have been a teacher, for only a teacher would know understand the type of problem that a beginning student would encounter.
• The fourth part has considerable interest for it claims that up to this work by al-Uqlidisi the Indian methods had been used with a dust board.
• However, al-Uqlidisi showed how to modify the methods for pen and paper use.
• Al-Uqlidisi's work is historically important as it is the earliest known text offering a direct treatment of decimal fractions.
• Al-Uqlidisi uses decimal fractions as such, appreciates the importance of a decimal sign, and suggests a good one.
• 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.
• Following Saidan's paper, some historians went even further in attributing to al-Uqlidisi the complete credit for giving the first complete description and applications of decimal fractions.
• The argument depends on how one interprets the following passage in al-Uqlidisi's treatise.
• unlike al-Samawal, al-Uqlidisi never formulates the idea of completing the sequence of powers of ten by that of their inverse after having defined the zero power.
• There is no disagreement on the fact that al-Uqlidisi made a major step forward.

Born about 920, possibly Damascus, Syria. Died about 980, possibly Damascus, Syria.

View full biography at MacTutor

Ancient Arab, Origin Syria, Special Numbers And Numerals

Thank you to the contributors under CC BY-SA 4.0!

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non-Github:
@J-J-O'Connor
@E-F-Robertson

### References

#### Adapted from other CC BY-SA 4.0 Sources:

1. Oâ€™Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive