What is abacus?
The abacus is a calculating device used from ancient times. It is thought that this simple apparatus had originated in Babylon about 5,000 years ago. In 19th and 20th century, it was still used in Japan, China, the Middle East, and Russia.
Resurgence of Abacus Learning
However, the awareness of the importance of Abacus and Mental Arithmetic was rekindled once again in the late 80s and early 90s especially after the reports of the First and Second International Comparative Studies of Mathematics Achievement conducted by the International Association for the Evaluation of Educational Achievement (IEA) were published. In both studies, the performance of the students from the Eastern countries was found to be consistently higher than the Western counterparts.
What are the main techniques of Abacus Learning?
- Use of Abacus: In this technique, we use an abacus to perform most arithmetic operations such as addition, subtraction, multiplication, division, square root, cubic root, etc.
- Visualization: Instead of manipulating a physical abacus, in this technique, calculations are done mentally with an imaged abacus, and such calculation method is the so-called ‘‘abacus-based mental calculation (AMC)“. AMC is an efficient calculation strategy that can be mastered by children through Abacus training.
About Abacus History & main types of Abacus:
It is the view of the historians that the first abacus consisted of a shallow tray filled with fine sand or dust and numbers were recorded and erased with a finger. It is also thought that the word abacus, might have come from the Semitic word for “dust,” abq.
A modern abacus is made of wood or plastic, consisting of a rectangular frame with at least nine vertical rods strung with movable beads. The number of vertical bars and beads on each bar varies with location and culture, but the basic function of the abacus remains the same.
Chinese Abacus or Suan-pan
The Chinese abacus has a horizontal bar which divides the frame into two parts. The classic version of Chinese Abacus is known as the suan-pan, or the “2/5 abacus,”. It is thought to have developed around C. E. 1200.
- In Suan-pan, the area above the horizontal bar, is called as heaven, and consists of two beads per vertical rod. Each of these beads has a value of five.
- The lower area is called as the earth. Each vertical rod in the earth area, contains five beads each, with each bead having a value of one.
- Each vertical rod represents a unit of ten. Calculation is done by moving beads toward or away from the horizontal divider.
Japanese Abacus or Soroban
In the mid – 1800s, the 2/5 abacus was replaced by the 1/5 abacus, and, by the 1930s, the most widely used form of abacus was the Japanese – made soroban, or 1/4 abacus.
- The numerical value of each bead depends on its location in the abacus. Each heaven bead has a value of five times that of an earth bead below it.
- Each rod represents columns of written numbers. Beads on the vertical rod farthest to the right have their values multiplied by one. On this rod, each earth bead is one and each heaven bead is five.
- Beads on the second rod from the right, however, have their value multiplied by 10. On this rod, each earth bead represents 10 and each heaven bead stands for 50. Beads on the third rod from the right have their value multiplied by 100, so that each earth bead represents 100 and each heaven bead stands for 500, and so on.