== Karya ==
is the author of several treatises on [[ mathematics]] and [[ astronomy]], some of which are lost.
His major work, ''Aryabhatiya'', a compendium of mathematics and astronomy, was extensively referred to in the Indian mathematical literature and has survived to modern times. The mathematical part of the ''Aryabhatiya'' covers arithmetic, algebra, plane trigonometry, and spherical trigonometry. It also contains continued [[fraction]]s, [[quadratic equation]]s, sums-of-power series, and a table of [[sine]]s.
The ''Arya-siddhanta '', a lost work on astronomical computations, is known through the writings of Aryabhata 's contemporary, [[Varahamihira]], and later mathematicians and commentators, including [[Brahmagupta]] and [[Bhaskara I]]. This work appears to be based on the older [[Surya Siddhanta]] and uses the midnight-day reckoning, as opposed to sunrise in ''Aryabhatiya''. It also contained a description of several astronomical instruments: the [[gnomon]] (''shanku-yantra''), a shadow instrument (''chhAyA-yantra''), possibly angle-measuring devices, semicircular and circular (''dhanur-yantra'' / ''chakra-yantra''), a cylindrical stick ''yasti-yantra'', an umbrella-shaped device called the ''chhatra-yantra'', and [[ water clock]] s of at least two types, bow-shaped and cylindrical.<ref name = Ansari/>
A third text, which may have survived in the [[ Arabic language|Arabic]] translation, is ''Al ntf'' or ''Al-nanf''. It claims that it is a translation by Aryabhata, but the Sanskrit name of this work is not known.
Probably dating from the 9th century, it is mentioned by the Persian scholar and chronicler of India, [[Abū Rayhān al-Bīrūnī]].<ref name = Ansari/>
=== Aryabhatiya ===