**190 CE**

The first mention of the suanpan in print, (Chinese abacus) which was widely used until the invention of the modern calculator. ^{1}

**639 CE**

Indian mathematician Brahmagupta was the first to describe the modern place-value numeral system.

**820 CE**

Persian mathematician, Muḥammad ibn Mūsā al-Khwārizmī, described the rudiments of modern algebra.

**850 CE**

Arab mathematician Al-Kindi (Alkindus), was a pioneer of cryptography. He gave the first known recorded explanation of cryptanalysis in A Manuscript on Deciphering Cryptographic Messages. ^{2}

**1000 CE**

Abū Rayhān al-Bīrūnī invented the Planisphere an early analog computer.