Abacuses pl. : of Abacus

Example:
What are the benefits of learning the abacus?

Taxonomy
abacus, beads, Nepohualtzintzin, wire, Russian abacus, Chinese abacus, suanpan, grooves, calculations, Roman abacus, the Chinese, Japanese abacus, the Roman, The Russian, bead wire, instrument, Abacus logic, School.

Defination from the web:
abacus, also called a counting frame, is a calculating tool used primarily in parts of Asia for performing arithmetic processes. Today, abacuses are often constructed as a bamboo frame with beads sliding on wires, but originally they were beans or stones moved in grooves in ...