The abacus is an antique tool used all over the world for calculation and computation. It has been largely replaced by calculators, but Abacus is fun to use. Here we will learn how to add and subtract by the old-fashion way.
Make yourself comfortable with the structure of the abacus. The abacus consists of two parts which are divided by the centre bar. Each part consists of columns of beads. The lower part usually consists of four beads and the upper part of one or two beads.
1. The beads in the lower part are assigned values randomly. For example, you may assign the beads in the rightmost rod a value of 1. Then you may subsequently assign a value of 10 to the rod to its left, and a value of 100 to the rod further left and so on and so forth.
Start with all beads at the bottom: Lean your abacus towards yourself so all beads will fall to the bottom. You need to clear the Abacus as no beads should touch the centre bar in the abacus. Hence the reading on abacus will be zero.
Write your first number
1. Break the number down into single digits. Let’s say break 13 into 1 tens plus 3 units.
2. Move, from the tens rod, a number of beads equal to the tens digit. In the above example, this number is one. Likewise move, from the units rod, a number of beads equal to the units digit. In above example, that number is 8, and there are only four beads. To overcome this problem, move one bead toward centre bar from the upper part of the abacus. That bead is equal to 5. Now just move 3 more beads from the lower part.
Place the second number: How you put the second number will depend whether you are working on addition or subtraction.
1. If you are working on addition, then divide the number into digits just like above and move up further beads in addition to those already up.
2. In case you are on subtraction, then also you need to break the digit in same manner as above but bring down beads from the ones already above.
Read your total: Count the number of beads in every rod. This will give you the value of each digit. Let’s say if you get a value at 100th rod as 1 bead and on 10th rod 4 beads and on the unit rod it is 8, this will give you a result of 148.
Apart from this, you need to remember if you are dealing with decimals, you can move the unit’s column to the left. Never forget that the abacus does not come up with the calculations, but it helps you to boost your skills on calculations.