An abacus is a calculation tool, often constructed as a wooden frame with beads sliding on wires. It was in use centuries before the adoption of the written Arabic numerals system. 
Although often attributed to the Chinese, the abacus is thought to to have been invented by the Babylonians around 2400 BC. The first abacus was almost certainly based on a flat stone covered with sand or dust. Lines were drawn in the sand and pebbles used to aid calculations. From this, a variety of abaci were developed; the most popular were based on the bi-quinary system, using a combination of two bases (base-2 and base-5) to represent decimal numbers.

The use of the word abacus dates back to before 1387 AD when a Middle English work borrowed the word from Latin to describe a sandboard abacus. The Latin word came from abakos, the Greek genitive form of abax ("calculating-table"). Because abax also had the sense of "table sprinkled with sand or dust, used for drawing geometric figures," it is speculated by some linguists that the Greek word may be derived from a Semitic root, abaq, the Hebrew word for "dust." Though details of the transmission are obscure, it may also be derived from the Phoenician word abak, meaning "sand".

The Chinese abacus usually has more than seven rods. There is one bead on each rod in the upper deck and four beads each in the lower deck for decimal computation. The beads are usually diamond shaped and made of a hard wood. The beads are counted by moving them up or down towards the beam. The abacus can be reset to the starting position instantly either by a quick jerk along the horizontal axis or by hand.

Chinese abaci can be used for functions other than counting. Unlike the simple counting board used in elementary schools, very efficient techniques have been developed to do multiplication, division, addition, subtraction, square root and cube root operations at high speed.

 Recent studies have shown that the abacus method of mental calculation is effective in the development of the right brain. At first, this idea was only a hypothesis, but the recent development of high-tech machinery has helped provide tangible research data.

Following are some of the positive effects that are observed if abacus training is provided at an early age.
·     Improvement in numerical memory.

·     Improvement of memory in spatial arrangement

·     Progress in solving general mathematical problems (basically four fundamental arithmetic operations)

·     Progress in the ability to calculate rapidly and accurately and to calculate mentally