· Basics · Java Applet
· Technique · The
· Salamis Tablet · Counting
Board · Roman Hand Abacus ·
Suan Pan · Soroban · Schoty
· Nepohualtzitzin · Khipu
· Lee Abacus
- Sarat Chandran and David A. Bagley's
incredible Java abacus with a built-in tutor for counting,
addition and subtraction.
· Multiplication &
Division · Square Roots
The Lee Abacus The manual for the Lee Abacus, c. 1958
is available as Text
Michael Mode builds exotic abaci as art objects.
Abacus Techniques by Totton Heffelfinger & Gary Flom.
Excerpts and Analysis
- In 1946, a contest held in Tokyo, pitted an
abacus against an electric calculator; the abacus won, of
Richard Feynman battles against the abacus; the
result is not surprising (if you know Feynman).
- An analysis contributed by David B. Kelley.
An analysis contributed by Steve Stephenson.
Steve Stephenson contributes another analysis on the Salamis
Tablet and the Roman Hand-Abacus and proposes a theory on how these
In this video, Steve Stephenson explains how to use a Counting
Board like the Salamis Tablet.
The Incan Khipu
String, and Knot, Theory of Inca
Writing by John Noble Wilford.
Talking Knots of the Incas by Viviano and Davide Domenici.
- An article about the dangers of
forgetting knowledge learned from the past, by Eugene Linden.
- Purchase or build an abacus
· An abacus for your Palm
· Books about the abacus
· Java applet source code
· The Mesoamerican abacus
The abacus in the classroom · Abacus lesson
plan · Math and science resources for
High-resolution photos of my abacus collection.
Updated: Fri 10 May 2013 03:50:29 PM EDT
Before you email me, please take a moment to read
this list of answers to questions I'm asked most often.
Just a small sampling of email I have had the
pleasure to receive.
In existence since 1995, this site has collected a
few awards and the Java applet appeared in several books and
The collected contributions of very many people made
this site possible.
Sorted list of accesses over the period of a year,
shows the popularity of individual abacus pages.
Would you consider translating one or more of these pages to
Español, Français, Português, Italiano, Deutsch?