Skip to main content

Abacus (The counting Machine)

The abacus is an ancient calculating machine. Thissimple apparatus is about 5,000 years old and is thought tohave originated in Babylon. As the concepts of zeroandArabic number notation became widespread,basic mathfunctions became simpler,and the use of the abacus dimin-ished. Most of the world employs adding machines,calcu-lators,and computers for mathematical calculations,buttoday Japan,China,the Middle East,and Russia still usethe abacus,and school children in these countries are oftentaught to use the abacus. In China,the abacus is called asuan pan,meaning counting tray. In Japan the abacus iscalled a soroban. The Japanese have yearly examinationsand competitions in computations on the soroban.Before the invention of counting machines,peopleused their fingers and toes,made marks in mud or sand,put notches in bones and wood,or used stones to count,calculate,and keep track of quantities. The first abaciwere shallow trays filled with a layer of fine sand ordust. Number symbols were marked and erased easilywith a finger. Some scientists think that the term abacuscomes from the Semitic word for dust,abq.

A modern abacus is made of wood or plastic. It isrectangular,often about the size of a shoe-box lid. With-in the rectangle,there are at least nine vertical rodsstrung with movable beads. The abacus is based on thedecimal system. Each rod represents columns of writtennumbers. For example,starting from the right and mov-ing left,the first rod represents ones,the second rod rep-resents tens,the third rod represents hundreds,and soforth. A horizontal crossbar is perpendicularto therods,separating the abacus into two unequal parts. The moveable beads are located either above or below thecrossbar Beads above the crossbar are called heaven pushed up to the crossbar. Number two would require two earth beads. For number five, only one heaven bead would to be pushed to the crossbar.  The number six would require one heaven (five units) plus one earth (one unit) bead.  The number 24 would use four earth beads on the first rod and two earth beads on the second rod.  The number 26 then, would use one heaven and one earth bead on the first rod, and two earth beads on the second rod.  Addition, subtraction, multiplication, and  division can be performed on an abacus.  Advanced abacus users can do lengthy multiplication and division problems, and even find the  square root or cube root of any number.


Comments

Popular posts from this blog

How Energy conversion from coal is done?

Single generator sets of over 600 MW are now used in the UK, though there are many smaller generators in use. A 600 MW generator can supplythe average needs of over 1 million UK households. Three or four such generators are typically installed in a single large coal-fired station which isoften sited close to a coal mine, away from the city dwellers who consume the electricity. Such generators are usually driven by a compound arrangement of highpressure, intermediate-pressure and low-pressure turbines, increasing in size as the pressure decreases. Modern turbines rotate in a speed range from 1500 to 3500 r.p.m., usually 3000 r.p.m. for the UK’s 50 Hz system. For large coal-fired plant the steam pressure could be 25 megapascals (MPa) with steam temperatures of 500–600 °C to improve the thermodynamic efficiency. In nuclear reactors, which operate under less demanding conditions, the steam is superheated to about 5 MPa and 300 °C. Modern water tube boilers are complex and have ...

All about Electronics & Instrumentation Engineering)(EI)

  Vision : To be globally recognized as a seat of learning and innovation in Electronics for application to Communication, Transportation, Defence, Industry, Health Care, Entertainment, and many other consumer products.  Mission : 1). To produce quality engineers in the field of Electronics and related domains.  2) To conduct research and develop products in the fields of Chip design, Communication Systems, Electronics Instrumentation, Signal Processing and other related areas with strong emphasis on critical state of the art applications.  3) To grow in the area of Design and Manufacturing of chips, boards and systems.     Program Educational Objectives :  I.  To provide students a successful career in industry that meets the needs of national and multinational companies.  II.  To develop the ability among students to synthesize data and technical concepts for application to electronic product design and to solve real...

5 TOP FACTS LIGHTHOUSES

1  The builder of the Lighthouse of Alexandria, Sostratus – disobeying orders from the pharaoh Ptolemy – engraved his name and a dedication to the sea gods on the tower base. Fame 2  The technical term for the study of lighthouses is ‘pharology’, a word derived from Pharos, the island upon which the great Lighthouse of Alexandria once stood. Academia 3  George Meade built many notable lighthouses in the US during the classical lighthouse period. He is remembered in history as the winning general in the Battle of Gettysburg. War 4  The tallest lighthouse in the world is the Yokohama Marine Tower in Yokohama, Japan. The structure fl ashes alternately green and red every 20 seconds. Tallest 5  Originally lighthouses were lit merely with open fi res, only later progressing through candles, lanterns and electric lights. Lanterns tended to use whale oil as fuel.