You probably have a Chinese abacus, the Suan Pan [1]. The (“16th century”) Japanese derivative, the Soroban [2] has a single pebble in the top registers. The former can do both quinary and decimal reckoning. The Russian Tchoty [3] does not divide the board, but rather uses 2 colors for beads.
If you are interested in a ~comprehensive treatment of the history and types of ‘counting boards’, K. Menninger’s Number Words and Number Symbols [4] (where I read about Kiyoshi Matsuzaki aka “the Hands” beating Pvt. Thomas Ian Wood and his electronic calculator) is a good resource. quinary and decimal variants are addressed in fair detail.
The section Counting Boards in Ancient Civilizations starts with the Salamis Tablet [5] and the Abax[6] depicted in use by a Persian calculator in the Darius Vase [7]. These boards didn’t have wires, so the ‘calculators’ used pebbles. Then we have next in progression the Roman hand-held abacus [8], which apparently found its way to East Asia and there it found a lasting appreciation and use, culminating in the two Chinese and Japanese variants noted above.
One of the surprising aspects of the discussion of the use of these instruments in Japan has to do with how they are used. I always thought the abacus delegated all the math to the device, but this is apparently not correct. Per Menninger, the reckoned must “constantly work the problems in his head”
From what I have read there is no direct evidence that an “abax” (Greek counting board) ever actually involved sand on a table; this claim has been repeated widely but seems to be an inference entirely based on etymological speculation.
The Darius vase shows a counting table with piles of tokens, but no indication of sand or people writing on an erasable surface (just some pre-established place markers for the pebbles to sit next to). https://upload.wikimedia.org/wikipedia/commons/2/24/Darius_v...
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While we are here, it should be noted that counting boards with coin-like tokens (comparable to the Salamis tablet or Darius vase image) were the dominant way of doing calculations in Europe up until about 300–500 years ago, with written arithmetic using Hindu numerals gradually taking over. A few centuries later and a 3000+ year-old counting-board culture has been almost completely erased.
If you are interested in a ~comprehensive treatment of the history and types of ‘counting boards’, K. Menninger’s Number Words and Number Symbols [4] (where I read about Kiyoshi Matsuzaki aka “the Hands” beating Pvt. Thomas Ian Wood and his electronic calculator) is a good resource. quinary and decimal variants are addressed in fair detail.
The section Counting Boards in Ancient Civilizations starts with the Salamis Tablet [5] and the Abax[6] depicted in use by a Persian calculator in the Darius Vase [7]. These boards didn’t have wires, so the ‘calculators’ used pebbles. Then we have next in progression the Roman hand-held abacus [8], which apparently found its way to East Asia and there it found a lasting appreciation and use, culminating in the two Chinese and Japanese variants noted above.
One of the surprising aspects of the discussion of the use of these instruments in Japan has to do with how they are used. I always thought the abacus delegated all the math to the device, but this is apparently not correct. Per Menninger, the reckoned must “constantly work the problems in his head”
[1]: https://en.wikipedia.org/wiki/Suanpan
[2]: https://en.wikipedia.org/wiki/Soroban
[3]: https://womenshistory.si.edu/object/tchoty-or-russian-abacus...
[4]: https://www.goodreads.com/book/show/1598307.Number_Words_and...
[5]: https://en.wikipedia.org/wiki/Salamis_Tablet
[6]: https://en.wikipedia.org/wiki/Sand_table
[7]: https://en.wikipedia.org/wiki/Darius_Vase
[8]: https://en.wikipedia.org/wiki/Roman_abacus