The Abacus is an apparatus used for Counting. Mathematical operations like Addition, Subtraction, Division and Multiplication can also be performed on a standard Abacus.The Abacus is typically constructed using various types of hardwoods and comes in different sizes. The frame of the Abacus has a series of vertical rods on which a number of wooden beads are allowed to slide freely. A horizontal beam separates the frame into two sections, named as the upper deck and the lower deck.


Basics
Place the Abacus flat on a table and control the beads with the fingers of one hand to perform the calculations. Value of each bead in the upper deck is five and value of a bead in the lower deck is one. Beads are considered counted, when moved towards the beam that separates the two decks.

The first column from the right extreme is the 'Ones/Unit' column; the second one from the right side is the 'Tens' column; the next one is the 'Hundreds' column, and so on. After 5 beads are counted in the lower deck, the result is "carried forward" to the upper deck; after both beads in the upper deck are counted, the result (10) is then carried to the left-most adjacent column. Floating point calculations are performed by designating a space between 2 columns as the decimal-point and all the rows to the right of that space represent fractional portions while all the rows to the left represent whole number digits.