Ancient Times 500 BCE - 500 CE
Counting and keeping track of the number of things was taking place long before the first counting devices. Marks in bones, scratches in sand and even crude counting tables existed, but deteriorated due to the materials with which they had been constructed. The oldest existing counting board is the Salamis Tablet. Made of white marble it dates back to Greek and Roman times circa 500 CE.
Middle Ages 500 CE - 1500
Medieval counting boards were made with grooves or rods that the counters were attached to. This allowed for portability and possibly accounts for how the abacus spread throughout the world via traveling merchants. The Chinese abacus, a Suan-pan, first appeared in 1200 CE. It was fashioned out of a wooden frame and had metal rods. It typically had 2 beads on the upper deck and 5 beads on the lower deck.
The introduction of the Hindu-Arabic Numbering system in Western Europe during the late part of the Middle Ages lead to the use of paper and pencil for arithmetic, causing the use of counting boards to all but disappear by 1500.
Modern Times 1500 - Present
Based on the pair of human hands, the Russian abacus, a Shoty, is ideal for a base-ten counting system. This abacus was also fashioned from wood and metal rods, however it used in a vertical position whereas the Chinese Suan-Pan and its Japanese counterpart are both set up horizontally.
Also ideal for a base-ten counting system is the Japanese abacus. Around 1600 CE, the Japanese modified the Chinese Suan-Pan into what is now the Soroban. It now contains only 1 bead on the upper deck and 4 on the lower. The Soroban is still in use today in Japan and around the world.
How to use an Abacus