what is abacus and how to learn
The abacus is a calculating tool used primarily in parts of Asia for performing arithmetic processes. It is also called a counting frame. They were beans or stones moved in grooves in sand or on tablets of wood, stone, or metal. Today, abacuses are often constructed as a bamboo frame with beads sliding on wires.
To know about how to represent the numbers on abacus please go through the below mentioned link.