Abacus and its history

What is an Abacus It is a Latin word, derived from the Greek word ABAX which means a calculating table. Brain-O-Magic Abacus At Brain-O-Magic we use the Japanese Abacus - the Soroban. Types of the Abacus and their history http://www.shuzan.jp/english/history/history.html As per Wikipedia The abacus, also called a counting frame, is a calculating tool used primarily in parts of Asia for performing arithmetic processes. Today, abacuses are often constructed as a bamboo frame with beads sliding on wires, but originally they were beans or stones moved in grooves in sand or on tablets of wood, stone, or metal. The abacus was in use centuries before the adoption of the written modern numeral system and is still widely used by merchants, traders and clerks in Asia, Africa, and elsewhere. At Brain-O-Magic we use the Japanese Abacus with one bead at the top having a value of 5 and four beads at the bottom each having a value of 1. In Japanese, the abacus is called Soroban (算盤, そろばん, lit. "Counting tray"), imported from China around 1600. The 1/4 abacus appeared circa 1930, and it is preferred and still manufactured in Japan today even with the proliferation, practicality, and affordability of pocket electronic calculators. The use of the Soroban is still taught in Japanese primary schools as a part of mathematics. A in the mid-fifteenth century, the Chinese abacus and its operational technique were introduced to Japan. Shortly afterward, Japan entered a long period of peace, which fostered the development of her cities and commerce. Mathematicians' constant and diligent study developed a distinct Japanese method of the Soroban operation different from the original Chinese method. The large-sized Chinese abacus was improved into a handier smaller-sized one. Towards the end of the nineteenth century, the Soroban with one five-unit counter and four one-unit counters on each rod came into use along with the older type which had one five-unit counter and five one-unit counters on each rod. In 1938, the technique of the Soroban operation was included in the national grade-school textbooks on arithmetic compiled by the Education Ministry. Today, the Soroban technique is a required study in the third and upper grades. The Soroban with one five-unit counter and four one-unit counters on each rod is the standard today. It should also be noted that the older Chinese division method, which makes use of the cumbersome division table, was formerly replaced by the Japanese division method, which makes use of the multiplication table. The inclusion of the Soroban technique in the curriculum of Japanese compulsory education and the enforcement of the Soroban efficiency tests system since its inception in 1928 have been the two major factors which have led to the present popularity of Soroban in Japan. In China, the abacus came into common use during the Ming Dynasty. A book titled Ch' o Ching Lu gives this proverbial expression:  “A servant, sometime after he is hired, comes to do nothing more than he is ordered to. Therefore, he is like an abacus counter.” A book written by Wu Ching-Hsin-Min in 1450 gives descriptions of the abacus. A large number of books published towards the end of the Ming Dynasty attest to the fact that the abacus had come into popular use. The abacus then had two counters above the bar and five below. This type of abacus is still being used in China these days.