Abacus

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*ABACUS*

An abacus is the earliest and most simple form of a calculator. All the arithmetical processes can be carried out on an abacus. This is done by changing the position of beads on counters.The most common type of abacus is a small rectangular frame with several fixed verticle rods. Beads or counters are on these rods. They are then able to slide up or down.
Each of the rods represents a decimal place. In a simple abacus (one rod only), each bead has the value of a single decimal place.Addition is done by moving beads together. Subtraction is done by moving beads away from other beads.The abacus can also be used for multiplication, division, and finding square roots.The earliest abacus was most likely a dust covered tray. Tally marks could be drawn in the dust and swept away with the hand.The problem with using an abacus is that a record of the arithmetic process is not kept. If a mistake is made, it is impossible to know where it was made.For those who are skilled in using an abacus, it is still the best tool for arithmetic processes other than multiplication.As written number systems developed, the abacus fell out of use.

Today, the abacus is primarily seen as a teaching tool for Kindergarten. It allows children to learn calculations and numbers with fun. The child uses his or her fingers to move the beads on the abacus and this collaborative movement of the fingers and the brain are responsible for creating a pictorial memory in the child’s brain. During abacus calculation, the child uses both his hands; this movement spurs activity in both left and right brains, thus initiating the development of cells. All this activity helps in nurturing the brain of the child making him much quicker and accurate in this process.This is mostly true in the Western world. In the Eastern world, the abacus is still a tool not only of education, but for tradesmen, business men, and race-track cashiers.

No matter how the abacus is used, it holds an important technological place in history.


Origins

The use of the word abacus dates from before 1387, when a Middle English work borrowed the word from Latin to describe a sand board abacus. The Latin word came from abakos, the Greek genitive form of abax ("calculating-table"). Because abax also had the sense of "table sprinkled with sand or dust, used for drawing geometric figures", some linguists speculate that the Greek word may be derived from a Semitic root, ābāq (pronounced "a-vak"), the Hebrew word for "dust". Though details of the transmission are obscure, it may also be derived from the Phoenician word abak, meaning "sand".

Babylonian abacus

Babylonians may have used the abacus for mathematical operations of addition and subtraction. However, this primitive device proved difficult to use for more complex calculations. Some scholars point to a character from the Babylonian cuneiform which may have been derived from a representation of the abacus.

Egyptian abacus

The use of the abacus in ancient Egypt is mentioned by the Greek historian Herodotus, who writes that the manner of its usage by the Egyptians was opposite in direction when compared with the Greek method. Archaeologists have found ancient disks of various sizes that are thought to have been used as counters. However, wall depictions of this instruments have not been discovered, casting some doubt over the extent of use of this instrument.

Greek abacus

A tablet found on the Greek island Salamis in 1846 dates back to 300 BC, making it the oldest counting board discovered so far. It is a slab of white marble 149 cm long, 75 cm wide, and 4.5 cm thick, on which are 5 groups of markings. In the center of the tablet is a set of 5 parallel lines equally divided by a vertical line, capped with a semi-circle at the intersection of the bottom-most horizontal line and the single vertical line. Below these lines is a wide space with a horizontal crack dividing it. Below this crack is another group of eleven parallel lines, again divided into two sections by a line perpendicular to them, but with the semi-circle at the top of the intersection; the third, sixth and ninth of these lines are marked with a cross where they intersect with the vertical line.

Roman abacus

The normal method of calculation in ancient Rome, as in Greece, was by moving counters on a smooth table. Originally pebbles, calculi, were used. Later, and in medieval Europe, jetons were manufactured. Marked lines indicated units, fives, tens etc. as in the Roman numeral system. This system of 'counter casting' continued into the late Roman empire and in medieval Europe, and persisted in limited use into the nineteenth century.
In addition to the more common method using loose counters, several specimens have been found of a Roman abacus. It has eight long grooves containing up to five beads in each and eight shorter grooves having either one or no beads in each.

Indian abacus

1st century sources, such as the Abhidharmakosa describe the knowledge and use of abacus in India.Around the 5th century, Indian clerks were already finding new ways of recording the contents of the Abacus. Hindu texts used the term shunya(means Zero) to indicate the empty column on the abacus.

Chinese abacus

Usually, a suanpan (an abacus of Chinese origin) is about 20 cm tall and it comes in various widths depending on the operator. It usually has more than seven rods. There are two beads on each rod in the upper deck and five beads each in the bottom for both decimal and hexadecimal computation. The beads are usually rounded and made of a hardwood. The beads are counted by moving them up or down towards the beam. The suanpan can be reset to the starting position instantly by a quick jerk along the horizontal axis to spin all the beads away from the horizontal beam at the center.

Japanese abacus

A soroban is a Japanese-modified version of the Chinese abacus. It is devised from the suanpan, imported from China to Japan through the Korean peninsula in the 15th century. Like the suanpan, the soroban is still used in Japan today, even with the proliferation, practicality, and affordability of pocket electronic calculators.

Korea also has its own abacus called the supan , which is basically the soroban before it took its modern form in the 1930s. The modern soroban also goes by this Korean name.

Russian abacus

The Russian abacus, the schoty , usually has a single slanted deck, with ten beads on each wire (except one wire which has four beads, for quarter-ruble fractions). This wire is usually near the user. (Older models have another 4-bead wire for quarter-kopeks, which were minted until 1916.) The Russian abacus is often used vertically, with wires from left to right in the manner of a book. The wires are usually bowed to bulge upward in the center, in order to keep the beads pinned to either of the two sides. It is cleared when all the beads are moved to the right. During manipulation, beads are moved to the left. For easy viewing, the middle 2 beads on each wire usually have a colour different from the other 8 beads. Likewise, the left bead of the thousands wire (and the million wire, if present) may have a different color.

The Russian abacus is still in use today in shops and markets throughout the former Soviet Union, although it is no longer taught in most schools.

School abacus

Around the world, abaci have been used in pre-schools and elementary schools as an aid in teaching the numeral system and arithmetic. In Western countries, a bead frame similar to the Russian abacus but with straight wires and a vertical frame has been common. It is still often seen as a plastic or wooden toy.

The most significant educational advantage of using an abacus, rather than loose beads or counters, when practicing counting and simple addition is that it gives the student an awareness of the groupings of 10 which are the foundation of our number system. Although adults take this base 10 structure for granted, it is actually difficult to learn. Many 6-year-olds can count to 100 by rote with only a slight awareness of the patterns involved.

Uses by the blind

An adapted abacus, 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.