What is ABACUS? ABACUS is a simple mental mathematical tool used for the purpose of calculation. It has been used for hundreds of years before the invention of computers; it dates as far back as 2400B.C. Many civilizations have developed their own version of the ABACUS tool. They were used in more Asian countries like Japan and Korea who named the tool the soroban, and in Russia where it is called a schoty. ABACUS is still being used in these countries and is now becoming mor