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 original lessons were taken from work by Luis Fernandes.
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.
SQRT operation is a new (19 Aug 2010 first draft - 1 Sep 2010 latest update) feature that is currently being added. Currently it solves perfect squares (0 - 104080804 tested with internal tester) in teach mode. Try it out with "10201v" in teach mode on a "Lee's Abacus". Unlike the other operations, sqrt reduces to an answer from which you must divide by 2. (You can try that out like "202/2", once sqrt operation gives you its "doubled" answer). This follows closely the work of Lee Kai-chen from his book "How to Learn Lee's Abacus". Let me know of any problems.
SQRT operation is a new (19 Aug 2010 first draft - 1 Sep 2010 latest update) feature that is currently being added. Currently it solves perfect squares (0 - 104080804 tested with internal tester) in teach mode. Try it out with "10201v" in teach mode on a "Lee's Abacus". Unlike the other operations, sqrt reduces to an answer from which you must divide by 2. (You can try that out like "202/2", once sqrt operation gives you its "doubled" answer). This follows closely the work of Lee Kai-chen from his book "How to Learn Lee's Abacus". Let me know of any problems.
Now handles floating point numbers too! Move the decimal point slider to the left before starting to increase precision. Now if you can just input negatives... the solution would involve turing the abacus sideways. ;)
Only Java version available. C version (kind of needs to run on X Window System though) available upon request.
CBRT operation yet to implement.
| 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, for warmer climate (no shoes), 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.
