The origins of the modern abacus stretch back almost 5000 years to ancient Mesopotamia where pebbles were moved against lines in the sand as a primitive but effective calculating device.
By the 5th century B.C., the Greeks had perfected a similar calculating system using a board, lines and pebbles.
In the following centuries the system was adopted and it changed to fit the needs of the countries that bordered the Mediterranean.
By the 1st Century A.D., the Romans had developed a board with slots and moveable counters that was distant cousin of the calculating devices in use today.
Many different cultures and civilizations around the globe at one time developed their own calculating devices.
The Russians came up with a curved model and in South America, the Incans invented a calculating system using different sized interlocking boxes to which pebbles were added or subtracted.
In China, the earlies form of the abacus dates from 2ed Century and was called SUANPAN in China.
Updated versions of the ancient SUANPAN are in use in China today.
The SUANPAN made its way to Japan from China in the 14th Century where it was called the SOROBAN.
The SOROBAN is very similar in form to the Chinese SUANPAN with one major difference.
Both the SUANPAN and the SOROBAN are comprised of a wood frame enclosing a series of vertical rods with beads that can be moved up or down.
The road are bisected by a single horizontal rod which separates the beads into two groups.
Here we find the major difference between the Japanese and Chinese models.
The Chinese SUWANPAN has two beads above and five below, the Japanese SOROBAN has four beads below but only a single beads above so although they are very similar in appearance and use, the calculating system is someone different.