Click on a abacus below to run Java
Abacus (mostly by David Bagley (help in initial conversion to Java by
Sarat Chandran)). Icons below are all zeroed and should give a rough
idea on what to expect.
There are two modes in menu that will help you learn
how to use the abacus:
the "demo" mode: here some static lessons are
given for the different types of abacus. The lessons include counting,
adding, subtracting, and multiplying.
the 
"teach" mode: here you learn at your own pace by entering your own
calculation like "A+B", "A-B", "A*B",
or "A/B" (where A>0 and result
positive). Pressing the enter key, will give you a step by step explanation and
show proper moves on the abacus. According to the books below, you are supposed
to start on left side, when adding or subtracting
multi-digit numbers. (There is a menu option "rightToLeftAdd", if you think
this is inefficient (similar one for multiplication "rightToLeftMult")).
Lee's Abacus is more suitable if you are learning multiplication and division,
as there are extra places to store operands.
Division is a feature just added.
"teach" mode: here you learn at your own pace by entering your own
calculation like "A+B", "A-B", "A*B",
or "A/B" (where A>0 and result
positive). Pressing the enter key, will give you a step by step explanation and
show proper moves on the abacus. According to the books below, you are supposed
to start on left side, when adding or subtracting
multi-digit numbers. (There is a menu option "rightToLeftAdd", if you think
this is inefficient (similar one for multiplication "rightToLeftMult")).
Lee's Abacus is more suitable if you are learning multiplication and division,
as there are extra places to store operands.
Division is a feature just added.
| Configurations (+ menu interface) | Applet |
|---|---|
| Chinese Abacus (also available Korean, Japanese, Roman, Russian, Danish) |
 |
| Lee's Abacus Principal Chinese with a Noneven Distributed 7 Rail Auxiliary |
 |
| Lee's Abacus Principal Korean with a Noneven Distributed 7 Rail Auxiliary |
 |
| Lee's Abacus Principal Chinese with a Even Distributed 9 Rail Auxiliary |
 |
The simplest configurations are the
below static versions. The menu interface control has been taken out
(except for some non-base 10 examples). This control feature is
available in the menu versions above. The control interface lets you
change formats easily. However, the static versions can be
modified by clicking on the abacus itself, then, for example, "i"
and "d" will increase and decrease the number of rails and "f"
will change formats.
A feature is the "complement"
function to help handle negatives in future.
feature is the "complement"
function to help handle negatives in future.
| Static Configurations | Applet |
|---|---|
| Chinese Abacus (Saun-pan) |
|
| Korean Abacus (Supan, AKA Japanese Soroban pre-WWII) |
 |
| Japanese Abacus (Soroban post-WWII) |
 |
| Roman Hand Abacus right most column twelfths and Ancient Roman Numerals in display |
 |
| Roman Hand Abacus right most column eighths and Modern Roman Numerals on abacus |
|
| Russian Abacus (Schoty) |
 |
| Old Russian Abacus (Schoty w/ 1/4 Kopek) |
 |
| Georgian Abacus (Russian base 20, warmer climate, do not take seriously) |
|
| Danish School Abacus |  |
| Mesoamerican Abacus (Nepohualtzintzin, similar to Japanese base 20) |
 |
| Babylonian Watch (proposed by author) |
 |
| Chinese Solid-And-Broken-Bar System (base 12) |
 |
| Base 16 Abacus (Japanese base 16) |
 |
| Lee's Abacus Principal Chinese with a Noneven Distributed 7 Rail Auxiliary |
|
| Lee's Abacus Principal Korean with a Noneven Distributed 7 Rail Auxiliary |
|
| Lee's Abacus Principal Chinese with a Even Distributed 9 Rail Auxiliary |
|
You can download the jar file (preserve the .jar extension),
and then it can be run as an application like
"java -jar AbacusApp.jar -rails=15" or
"java -jar AbacusApp.jar -lee=1 -leftAuxRails=9 -rightAuxRails=9".
The X Manual Page is written for the X version but may be useful
to understanding the Java program.
(Using Javascript, I used to have resizable scaling links but seemed
to crash browsers randomly.)
| Source Code | X Manual Page | Javadoc | Jar File |
|---|---|---|---|
| abacus.zip | xabacus | AbacusApplet | AbacusApp.jar |
See project notes for todo list and history.
Please let me know if I left
out anything.
