Abacus (2400BC)

The abacus is a calculating tool used primarily in parts of Asia for performing arithmetic processes. It was probably first developed in Sumer, and evidence has been found for its use in Ancient Egypt and Persia, as well as later variants in Ancient Greece and Rome, where often counters were moved on marked tables to perform basic arithmetic. The Romans developed a hand abacus, probably the first portable calculating device for engineers and merchants, although it was less capable than its predecessors. The Chinese abacus, which dates from perhaps the second century BC, provides more sophistication, enabling more complex computation including division and square and cube roots.

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