Al-Mansur founds Baghdad

The record shows that numerical astronomy and chronological calculation flourished in Mesopotamia centuries before classical Greek science.

Aryabhata's parameters are reckoned for mean noon at Ujjain on 21 March 499, giving his mathematical astronomy a precise temporal starting point.

Aryabhata used sine tables and algorithms to calculate celestial motion, helping establish a powerful Indian computational tradition.

His verse describes a rule yielding 3.1416, demonstrating sophisticated numerical work expressed through Sanskrit mnemonic poetry.

Aryabhata's notation encoded numbers through syllables, showing that mathematical representation can take forms other than modern written numerals.

Naubakht and Masha'allah reportedly selected an astrologically auspicious moment, illustrating the close relationship between mathematical astronomy and state planning.

The city's multilingual scholarly environment later supported translations and original work in arithmetic, algebra, geometry and astronomy.

Baghdad's planned circular form joined surveying, geometry, architecture and imperial symbolism in a major urban project.

Al-Azhar opened in Fatimid Cairo and developed into a long-lived institution of learning.

Alongside religious and linguistic studies, scholars taught inheritance arithmetic, astronomy, timekeeping and related mathematical subjects.