A Soroban Beats an Electric Calculator (1946) | Hacker News Reader

A Soroban Beats an Electric Calculator (1946)

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43 pointseternalban11 comments

I have an abacus and an instruction book on how to use it for decimal calculations. The five beads on the bottom each represent one, and a bead on the top represents 5 - yes: ten can be represented in two ways: a 5 bead and all five one beads, or by 0 beads on that digit's rod, and a one bead on the rod immediately to the left. You achieve proficiency by translating addition and subtraction tables into sqeezes and separations of bead patterns.

But why are there TWO beads at the top? Per instructions, one of them is never used!

After many years, I read that certain markets had a tradition of using hexadecimal(!) in which the two five beads and the five one beads gave an exhaustve range of 0 to 15. When I retire, I'm going to spend a few weeks learning the hexadecimal addition, subtraction, multiplication, and division tables and get them into my fingers. Finally, a superpower!

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”

[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

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...

* * *

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.

My father had a soroban that he had bought in Japan just after World War II, when he was in the U.S. Navy, and when I was around ten years old I got an instruction book and learned the basics. I never got very fast, but some Japanese-American friends had learned soroban and were pretty good. This was in Southern California in the 1960s.

I moved to Japan in 1983. For the next decade or so, I often saw clerks using soroban in offices, shops, department stores, and even banks. It’s been a long time, though, since I last saw one in action. But soroban basics are still part of the elementary-school curriculum, and there’s a private school that teaches soroban a few blocks from where I live in Yokohama.

Some sorobanists (?) are able to do rapid mental arithmetic with large numbers by visualizing the beads in their mind.

oh yeah i'm sure doing this sort of manipulations helps learning how to play with numbers wider and faster in your mind too.

it's an embodiment of the possibility to transform numbers how you need them to

Flash Anzan (mental abacus) techniques are always a notable topic[1][2].

As a sibling suggests, perhaps what you have is a Chinese abacus, which may be different in some sense; I would not know. In any case, I had assumed only decimal varieties existed and perhaps some sexagesimal configuration from antiquity.

I'd always fantasized about commissioning the builds of hexadecimal sorobans and mentally imprinting on them to the point of being able to perform immediate register math while debugging assembly for CTF challenges and the like. Maybe that could add an interesting dimension to the hobby :)

[1] Terrifyingly quick use of a soroban: https://www.youtube.com/watch?v=0_11-FZpc1c

[2] Flash Anzan/Mental abacus competition snippets: https://www.youtube.com/watch?v=mPLt1ujt5qE

The soroban uses rods with 4+1 beads. These amounts of beads is enough to represent decimal numbers.

And the ones with 5+2 beads rods are used to represent hexadecimal numbers. This was the configuration of the abacus imported from China, the suanpan.

Reminds me of Feynman's interaction with an Abacus Salesman in "Surely, You're Joking, Mr. Feynman!".

https://www.ee.ryerson.ca/~elf/abacus/feynman.html

Also: Feynman vs the abacus: https://www.ee.ryerson.ca/~elf/abacus/feynman.html

This guy was clearly a mentat.

early mechanical sympathy

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