These seven small, differently shaped clay objects were found in the ancient Sumerian city of Uruk in Mesopotamia. They are replicas of originals housed in the German Archaeological Institute in Berlin.
These so-called calculi were used as markers for certain amounts of commercial ware. As abstract counting was not yet known, one used specific markers for certain amounts of specific goods. When a contract had been agreed, these markers were deposited in a sealed clay casket. If a contract was completed or altered, the seal was broken in order to check the markers.