**Mental calculation**
is the practice of doing mathematical calculations using only the human
brain, with no help from any computing devices (**Wikipedia**). Mental calculation is
said to improve mental capability, speed of response, memory power and
concentration.

One way to practice mental
calculation is using **Abacus System**. The Abacus System
of mental calculation is a system where users mentally visualize an
abacus to do calculations. No physical abacus is used; only the answers
are written down. This system is being propagated in Malaysia, South
Korea, Thailand, Singapore and Japan.

The Abacus method of mental
calculation helps development of the right brain. In this method, the
learners manipulate abacus beads in their head to carry out a
calculation. Recent studies have proven that the Abacus method of
mental calculation is extremely effective in activating the right
brain.