How To Use Abacus: Abacus Operations

Abacus Parts

Figure below shows different parts of abacus, abacus in olden days were made of wood and now days it’s made from plastic. Abacus mainly consists of

• Frame (outer body it holds rods, bar and beads)

• Bar (separates upper beads from lower beads)

• Rods (to hold beads)

• Beads (they arebi conical in shape)

• House points(reference points to start calculations)

Abacus is made up of a frame with vertical rods on which beads move up and down. Dividing the upper and lower portion of the abacus is a horizontal bar called a beam or reckoning bar .

On a modern-day soroban, one bead sits above the beam and four beads sit below. The beads above the beam are often called heaven beads and each has a value of 5 (five). The beads below are often called earth beads and each has a value of 1(one).

Along the length of the beam, you'll notice that every third rod is marked with a dot and is called house point . These specially marked rods are called unit rods because any one of them can be designated to carry the unit number. While the abacus operator makes the final decision as to which rod will carry the unit number, it is common practice to choose a unit rod just to the right of center on the abacus.

In Japan, the art of using the abacus has been carefully cultivated : in 1928, abacus examination were conducted by Japan Chambers of Commerce and Industry, with more than a million candidates sitting the test by 1959. Although complex calculations are now performed out by computers, the abacus is still in use in some offices and shops, alongside computers and electronic calculators.

Abacus Arithmetic Operation