Editing Number theory (section)

==== Arithmetic in the Islamic golden age ====
{{Further|Mathematics in medieval Islam|Islamic Golden Age}}

[[File:Selenographia 1647 (122459248) (cropped).jpg|upright=0.8|thumb|[[Al-Haytham]] as seen by the West: on the frontispiece of ''[[Selenographia]]'' Alhasen{{sic}} represents knowledge through reason and Galileo knowledge through the senses.]]

In the early ninth century, the caliph [[al-Ma'mun]] ordered translations of many Greek mathematical works and at least one Sanskrit work (the ''Sindhind'', which may<ref>{{harvnb|Colebrooke|1817|p=lxv}}, cited in {{harvnb|Hopkins|1990|p=302}}. See also the preface in
{{harvnb|Sachau|Bīrūni|1888}} cited in {{harvnb|Smith|1958|pp=168}}</ref> or may not<ref name="Plofnot">{{harvnb|Pingree|1968|pp=97–125}}, and {{harvnb|Pingree|1970|pp=103–123}}, cited in {{harvnb|Plofker|2008|p=256}}.</ref> be Brahmagupta's [[Brāhmasphuṭasiddhānta]]).
Diophantus's main work, the ''Arithmetica'', was translated into Arabic by [[Qusta ibn Luqa]] (820–912).
Part of the treatise ''al-Fakhri'' (by [[al-Karajī]], 953&nbsp;– c.&nbsp;1029) builds on it to some extent. According to Rashed Roshdi, Al-Karajī's contemporary [[Ibn al-Haytham]] knew{{sfn|Rashed|1980|pp=305–321}} what would later be called [[Wilson's theorem]].