October last year, I have introduced how to represent numbers using the Japanese abacus. In this post, I am going to teach you how to add and subtract using it. If you are not familiar on how to represent numbers in abacus, please read the first part of this series by clicking the link above. You have to understand the representation in order to follow the tutorial below.
Note that although abacus is not needed in the calculations below since it can be done mentally, calculations done in abacus in real life involve large numbers or even those with decimals. The examples below will only give you an overview of how calculations are made and some of the strategies used. » Read more
In Japanese language, the abacus is called soroban. In this tutorial, we are going to learn how to use the soroban. In Japan, students learn to use abacus formally in the third grade.
Believe it or not, in these modern time, some tellers in Japan still use abacus. And when they calculate, they are almost as fast as when using a calculator. Or maybe even faster.
Shown above is a drawing representing a Japanese abacus. » Read more
Before computers, there were abaci (plural of abacus). They were used as a calculation tool for hundreds of years. They were popular to the Greeks, Romans, Chinese, Japanese and Koreans.
However, history tells us that there were way earlier versions of the modern abaci we know. According to Wikipedia, they existed in Sumeria as early as 2700 BC. » Read more