The Abacus: Index

Introducing: The Abacus

The first step in learning to use an abacus is to identify its parts, then learn the basic operations. An interactive Java applet is available for practice.

History of the Abacus

How the modern abacus evolved from primitive stone counters in the sand, to the Salamis tablet, to the Roman Hand Abacus that travelled to Asia via the Silk Road.

The Abacus vs. The Electric Calculator

In 1946, a contest was held in Tokyo pitting an abacus against an electric calculator; the abacus won, of course.

Lee Kai-chen Abacus

The latest and possibly final version of the abacus happened in 1956. Multiplication and division are faster and square roots and cubic roots can be calculated with this model.

ARTICLES & ANALYSIS

Articles, excerpts and reader-submitted analyses related to the abacus.

Feynman vs. The Abacus, by Richard Feynman: Feynman matches wits with an abacus salesman in Brazil.
Comparing the Chinese and Mesoamerican Abacus, by David B. Kelley: The similarities in the Chinese solid-and-broken-bar and the Mesoamerican bar-and-dot number symbols suggests a relationship between the two systems.
The Roman Hand-Abacus, by Steve Stephenson: "The Romans developed their hand-abacus as a portable counting board— the first portable calculating device for both engineers and businessmen."
String, and Knot, Theory of Inca Writing by John Noble Wilford.: "Although they were probably mainly accounting tools, a growing number of researchers now think that some khipu were non-numerical and may have been an early form of writing."
Lost Tribes, Lost Knowledge, by Eugene Linden.: "Today, with little notice, more vast archives of knowledge and expertise are spilling into oblivion, leaving humanity in danger of losing its past and perhaps jeopardizing its future as well."