Mesopotamian mathematics

Early examples of mathematical writing appeared in Mesopotamia, between the rivers Tigris and Euphrates in present-day Iraq. A Sumerian accounting tablet from around 3000 BC features commodities such as barley; the three thumb-nail indentations represent numbers. The Mesopotamian (or Babylonian) number system became a sexagesimal one, based on 60, which we still use in our measurement of time.
 The Mesopotamians later imprinted their mathematics with a wedge-shaped stylus on damp clay which was then baked in the sun. Thousands of these cuneiform clay tablets from 1900 to 1600 BC survive, and show a good understanding of arithmetic (including a very accurate value for 2), algebra (the solution of linear and quadratic equations) and geometry (the calculation of areas and volumes).
The Mesopotamians also studied astronomy and were able to predict eclipses; in 164 BC they observed the comet now known as Halley’s comet – not in 2349 BC as stated on the stamp.
[Austria 1965; Bhutan 1986; Venda 1982]