Sunday, October 2, 2011

The Square Root of Tradition

For one who frequents places selling old stuff—junk shops on one street, antique shops on another, and roadside stalls at the next—it’s difficult to always recall the details of one or two long ago purchases. Easier to remember the flea market and thrift shop buys in most cases, and hard to dredge up shop details for stuff dug out of dusty corners in backstreet China or Singapore. That is the case with a couple of Chinese suànpán, or abacuses I’ve had for a while. One of the two came from a ‘garage sale’ spread across the wide entrance stairs at a Tokyo’s train station, and the other…a small antique store in Bangkok sounds right, but the memory is fuzzy now.

Most of us are familiar with the old-style counting device called an abacus, if not the look, then maybe the purpose. Hard to say for sure if the Chinese got the idea from the Romans, or vice versa, but there is a description of one in a Chinese book dating to 190 AD. The Chinese call an abacus a suànpán, and moving through Korea to Japan around 1600 it came to be called a soraban. The Chinese suànpán and Japanese soraban differ slightly, and at the times I bought the two shown here, both to my mind were a soraban. It was only later that a comparison of the Chinese and Japanese versions showed a difference in the number of beads in the top deck: the Chinese suànpán has two beads in the top deck, the Japanese soraban only one.

From that standpoint the two examples I have are clearly Chinese in origin. That aside, whether it be one or the other, both versions of the abacus were designed for counting and calculation in days before the invention of adding machines or calculator. Efficient techniques for doing high speed multiplication, division, subtraction, square root and cube root have been developed for these old tools, and they are still used and taught in both China and Japan. Not sure if there is an argument that an abacus can compare with modern calculation tools in terms of speed, but there are still those who embrace the traditional system and continue to follow the old way.

A suànpán usually has more than seven vertical rods divided by an horizontal beam, but whatever the number it is always an odd number. There are two beads on each rod in the upper deck called ‘heaven,’ and five beads on each rod in the bottom deck called ‘earth.’ The beads are rounded and made of a hardwood, often bamboo. Counting is done by moving the beads up or down toward the beam. Those at the top have a value of five, those at the bottom one. The two that I have are different in that the smaller one has only five rods of beads, and the larger example eleven. Without any understanding of the method for using them, I can’t comment on the plus or minus factor related to the number of vertical rods—five, eleven, thirteen or more. For those interested in one man’s experience of learning the system, this link offers a good example.

Unable to say what the case is in China today, I can say that the facility of using a soraban is still an active skill in Japan. Interested students can find a soraban school not far away wherever the home neighborhood, and basics are still taught in elementary school math classes, unless it has changed in the past year or two. Unlikely that you will see a Japanese clerk in a department store or modern business using a soraban, but there are many small businesses run by people who keep a soraban right beside their handheld calculator. My local stationery store aunty in Kugayama kept her soraban right out on the register counter, using it countless times during my years as a regular customer.


  1. The abacus has always fascinated me. Maybe I will find the time to click the link and learn about how to use it. The are beautiful pieces of art as far as I'm concerned. An interesting post!

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Oak Hill, Florida, United States
A longtime expat relearning the footwork of life in America