An abacus is an old tool used for arithmetic. It is still used in some parts of the world, and it is well suited for use in shops and street markets. Sometimes blind people use an abacus, because they can feel the numbers easily. The most common abacuses work by moving beads on rods.
There is a common Chinese abacus. This abacus is split into two kinds of basic rows, the top is for the "5"s, and the bottom is for the "ones". There are one or two beads in the top rows, and four or five beads in the bottom ones. For example, 8 is one bead on top and 3 below, because 5 + 3 = 8. Every column represents a different digit.
Etymology[change | change source]
The use of the word abacus dates from before 1387 AD, when the word was got from Latin to describe a sandboard abacus. The Latin word came from ancient Greek ἄβαξ (abax) which means something without base, or (improperly) any piece of rectangular board or plank.
Both abacuses' and abaci are used as plurals. The user of an abacus is called an abacist (soft or hard 'c').
Japan[change | change source]
There is a Japanese version of the abacus called the 'soroban'. It works in essentially the same way.
Other websites[change | change source]
|Wikisource has the text of the 1911 Encyclopædia Britannica article Abacus.|
|Wikimedia Commons has media related to Abacus.|
|The English Wikibooks has more information on:|
General and historical articles[change | change source]
Tutorials[change | change source]
- Manual de uso del Abaco Japonés Soroban Archived 2006-05-24 at the Wayback Machine
- Min Multimedia
- Suan Pan Archived 2001-02-21 at the Wayback Machine
- Abacus: Mystery of the Bead - an Abacus Manual
Abacus curiosities[change | change source]
- Abacus in various number systems
- Java applet of Chinese, Japanese and Russian abaci Archived 2004-10-09 at the Wayback Machine
- An atomic-scale abacus