Abacus Calculation Techniques
Number representation on the abacus
ABACUS is a simple calculating tool used to do all the basic arithmetic calculations like addition, subtraction, multiplication and division.
Abacus consist of rods in which beads move up and down.
A beam divides the abacus rod into two parts. The lower part has 4 beads known as the lower bead or earth bead. The upper part has one bead known as the upper bead or the heaven bead. Each lower bead has a value of “1” and each upper bead has a value of “5”. The beads are moved up and down the rods with the help of fingers. The thumb and the forefinger of our right hand and the forefinger and middle finger of our left hand are used to move the beads. There is a unit point (a white dot) marked at every 3rd rod on the abacus. This rod indicate the unit place value rod and the rods towards the left of this unit rod would be tens’ rod, hundreds’ rod, thousands’ rod etc. The rod on the right hand side of the unit rod would be used to represent the decimal place value digits.
Before using the abacus, it should be made sure that the value on each rods are in the neutral position representing “0”.
Now suppose we need to represent no. “7” on the abacus. So with the thumb finger of the right hand need to move two lower beads up and with the forefinger need to move one upper beads down.
Next representing no. “76” on the abacus. With the thumb of the right hand move one lower bead up on the unit rod and with forefinger move one upper bead down. Next in the tens’ rod with the left hand forefinger move two lower beads up and with the middle finger move one upper bead down.
Let’s try representing no. “958” on the abacus. With the thumb of the right hand move three lower beads up and with the forefinger move one upper bead down on the unit rod. Next with the middle finger of the left hand move one upper bead down in the tens’ rod. And lastly with the forefinger and the middle finger of the left hand move all the beads in the hundredth rod simultaneously towards the beam.
Learning number representation on the abacus correctly is very important. It is possible with thorough practice. Once it is achieved, need to start doing mental calculations by making images of the abacus in the brain and thinking of what would be the position the lower and the upper beads for a particular number.
So we can conclude that abacus way of calculation is easy to learn, but to master it regular practice is needed.