what is an abacus?  

An abacus is a device used for addition and subtraction, and the related operations of multiplication and division. It does not require the use of pen and paper, and it's good for any base number system.

There are two basic forms for the abacus: a specially marked flat surface used with counters (counting table), or a frame with beads strung on wires (bead frame).

Answered by Shobhit , an ibibo Master, at 2:51 PM on May 11, 2008

Abacus is a Latin word that has its origins in the Greek words abax or abakon (meaning "table" or "tablet") which in turn, possibly originated from the Semitic word abq, meaning "sand" 1.
Why does the abacus exist?

It is difficult to imagine counting without numbers, but there was a time when written numbers did not exist. The earliest counting device was the human hand and its fingers. Then, as larger quantities (larger than ten human-fingers could represent) were counted, various natural items like pebbles and twigs were used to help count. Merchants who traded goods not only needed a way to count goods they bought and sold, but also to calculate the cost of those goods. Until numbers were invented, counting devices were used to make everyday calculations. The abacus is one of many counting devices invented to help count large numbers.
The difference between a counting board and an abacus

It is important to distinguish the early abacuses (or abaci) known as counting boards from the modern abaci. The counting board is a piece of wood, stone or metal with carved grooves or painted lines between which beads, pebbles or metal discs were moved. The abacus is a device, usually of wood (plastic, in recent times), having a frame that holds rods with freely-sliding beads mounted on them.

Both the abacus and the counting board are mechanical aids used for counting; they are not calculators in the sense we use the word today. The person operating the abacus performs calculations in their head and uses the abacus as a physical aid to keep track of the sums, the carrys, etc.
What did the first counting board look like?

The earliest counting boards are forever lost because of the perishable materials used in their construction. However, educated guesses can be made about their construction, based on early writings of Plutarch (a priest at the Oracle at Delphi) and others.

In outdoor markets of those times, the simplest counting board involved drawing lines in the sand with ones fingers or with a stylus, and placing pebbles between those lines as place-holders representing numbers (the spaces between 2 lines would represent the units 10s, 100s, etc.). The more affluent people, could afford small wooden tables having raised borders that were filled with sand (usually coloured blue or green). A benefit of these counting boards on tables, was that they could be moved without disturbing the calculation— the table could be picked up and carried indoors.

With the need for portable devices, wooden boards with grooves carved into the surface were then created and wooden markers (small discs) were used as place-holders. The wooden boards then gave way to even more more durable materials like marble and metal (bronze) used with stone or metal markers.

Answered by Sharad Singh , an ibibo Master, at 1:59 PM on May 02, 2008

well Raksha, At first the term abacus refers to a sand covered table upon which figures were inscribed using a stylus. There is a suspicion that the abacus had a semitic origin. A cuneiform sign among the ruins at Nippur(Shid») resembles its form (a calculating table).The term abacus is refers to the flat square slab of masonry that forms the uppermost member or division of the capital of a column, immediately under the architrave. The term is also used to describe a tablet, panel, or compartment in ornamented or mosaic work.

Answered by Uttam , an ibibo Master, at 10:18 AM on May 01, 2008

this is nothing but are system for calculating or adding which consist of horizontal bar and some beads on it

Answered by sharda , an ibibo Advisor, at 11:26 PM on April 30, 2008

An adapted abacus, invented by Helen Keller, called a Cranmer abacus is still commonly used by individuals who are blind. A piece of soft fabric or rubber is placed behind the beads so that they do not move inadvertently. This keeps the beads in place while the users feel or manipulate them. They use an abacus to perform the mathematical functions multiplication, division, addition, subtraction, square root and cubic root.
Although blind students have benefited from talking calculators, the abacus is still very often taught to these students in early grades, both in public schools and state schools for the blind. The abacus teaches math skills that can never be replaced with talking calculators and is an important learning tool for blind students. Blind students also complete math assignments using a braille-writer and Nemeth code (a type of braille code for math) but large multiplication and long division problems can be long and difficult. The abacus gives blind and visually impaired students a tool to compute math problems that equals the speed and mathematical knowledge required by their sighted peers using pencil and paper. Many blind people find this number machine a very useful tool throughout life.

Answered by bhanu pratap , an ibibo Citizen, at 5:12 PM on April 23, 2008

An abacus, also called a counting frame, is a calculating tool for performing arithmetic processes. Nowadays, abaci are often constructed as a wooden frame with beads sliding on wires, but originally they were beads or stones moved in grooves in sand or on tablets of wood, stone, or metal. The abacus was in use centuries before the adoption of the written modern numeral system and is still widely used by merchants and clerks in China, Japan, Africa, India and elsewhere.
The user of an abacus is called an abacist; he or she slides the beads of the abacus by hand.[1

Answered by yogesh , an ibibo Citizen, at 5:08 PM on April 23, 2008

"The abacus is a device, usually of wood (plastic, in recent times), having a frame that holds rods with freely-sliding beads mounted on them."
The use of the abacus was pre-dated by the use of counting boards. A counting board had grooves along which one could slide beads or stones. The beads or stones did not have holes in them but only grooves along which they moved on the counting board. "The oldest surviving counting board is the Salamis tablet (originally thought to be a gaming board), used by the Babylonians circa 300 B.C., discovered in 1846 on the island of Salamis."2 "The oldest surviving counting board is the Salamis tablet (originally thought to be a gaming board), used by the Babylonians circa 300 B.C., discovered in 1846 on the island of Salamis. "2 Ancient Counting Boards is a Web site that further chronicles the history and use of counting boards, the Salamis tablet(about 300 B.C.) and the improvements of the early counting tablets, how they evolved into the first Roman abacus.

Around 1000 AD the Aztec peoples invented a device similar to an abacus which used corn kernels threaded through wooden frames. This was known as a Nepohualtzitzin.3 An Aztec abacus would have seven "beads" by thirteen columns5. This abacus dated to around 900 A.D.6.

In an article attributed to Mr. Du Feibao1 the abacus was invented in China having already been "mentioned in a book of the Eastern Han Dynasty, namely Supplementary Notes of the Art of Figures written by Xu Yue about the year 190 A.D." It was during the Song Dynasty (960-1127) that Zhang Zeduan at Qingming Festival painted his famous long scroll, Riverside Scences, picturing an abacus lying beside an account book.1 The abacus was known to the Chinese as suan-pan. 3
Mr. Du Feibao states in his article that the abacus was introduced into Japan during the Ming Dynasty(1368-1644

Answered by anil kumar , an ibibo Citizen, at 4:59 PM on April 23, 2008

The image on the right is a cover of a manual published in 1958 by Lee Kai-chen, the inventor of this "new" abacus designed with 4 decks (it combines two abaci; the top abacus is a small 1/4 soroban and the bottom one is a 2/5 suan-pan).
The author claims that multiplication and division are easier using this modified abacus and includes instructions for determining square roots and cubic roots of numbers.

Answered by amit , an ibibo Citizen, at 4:55 PM on April 23, 2008

An abacus is a device used for addition and subtraction, and the related operations of multiplication and division. It does not require the use of pen and paper, and it's good for any base number system. There are two basic forms for the abacus: a specially marked flat surface used with counters (counting table), or a frame with beads strung on wires (bead frame). (5)
The name Abacus derives from the Greek word ABAX meaning table or board covered with dust. The origins of the Abacus are buried deep in the history of mankind. But it is generaly assumed that the origins of the Abacus lies in the Middle East some where in the period known as the Early Middle Ages. The model developed during that period had a wooden frame with several wires each strung with 10 beads. Three more than the Abaci we know now from Asia.
It is known that in its 'modern' form - 7 beads per string - the abacus appeared in China between the 12th and 13th century AD.
The abacus was most probably imported by merchants traveling to China, it migrated to Korea (appr 1400) and later Japan (appr 1600). The abacus in Europe was in use until the 18th century and is still in use in the Orient. The Abacus is still taught in the Far East as regular school training, and is used commonly in many places in many countries. Also in some enclaves(4) in the western world were people are living from the orient; Russia, China, Vietnam, Korea etc.
In 1947 a contest between a Japanese Abacist (Kiyoshu Matzuzake) and a US Army private (Tom Wood) with an electrically driven mechanical calculator was held for 2 days resulting in an unmistakable victory for the Abacist, four out of five. (3)

Answered by savesh singh , an ibibo Citizen, at 4:41 PM on April 23, 2008

An abacus is a calculator used first by the Chinese since about 500 BC, for addition, subtraction, multiplication, and division, as well as fractions and square root. It consists of a wood frame divided into 2 parts separated by a beam, with an upper deck of 2 rows of beads and a lower deck of 5 rows of beads. There is a series of vertical rods on which wooden beads are allowed to slide freely. Its inventor is unknown. However, the abacus as we know it today did not appear in China until about 1200 A.D.

Answered by khushvinder , an ibibo Citizen, at 4:23 PM on April 23, 2008