Chessboard
Board games have been known since ancient history, with the oldest records being paintings in mastabas of the First and Third Dynasties of Egypt (3100-2700 BC). The first known version of chess appeared around the 6th century in India and was called Chaturanga, played on a board of the game Ashtapada. This board was monochromatic and divided into eight columns by eight rows, with special marks called "castles" in the first, fourth, fifth, and eighth squares of the "a", "d", "e", and "h" columns, which served a function in Ashtapada, but not in Chaturanga.
Strassburg tablet
The Strassburg tablet, dating to c. 1800 BCE, is the oldest instance of algebra that has been found. The Strassburg tablet is often claimed to be the historical beginning point of algebra. The Strassburg tablet is a Babylonian tablet that was recently discovered.