Abacus
Introduction The abacus is a mechanical instrument used for counting and a wide range of mathematical calculations. A standard abacus’ abilities include: addition, subtraction, multiplication, division, and the extraction of square and cube roots. The abacus is typically constructed from some type of hardwood, and can be found in varying sizes. The abacus is made up of an outer frame with a series of vertical rods. ... There is a horizontal beam that runs through the frame, separating the beads into two segments, called the upper deck and the lower deck: The abacus above an example of the one-four abacus. ... Another common type of abacus is the two-five abacus. ... Each row of beads to the right of “unit place” decreases by ten fold (allowing the abacus to be used for decimals as well as rather large numbers, depending on the number of rods the abacus has). If the dot (unit place) on the above diagram was to be removed, the abacus would not be able to display decimals, and therefore the rightmost column would represent the ones, the next would represent the tens, and so on (allowing for even greater numbers to be displayed). ... This makes the abacus very versatile. To use the abacus, one generally places it on a flat surface or one’s lap, and begins by moving all of the beads away from the central beam (in the direction of the frame). ... Once the upper beads are counted (for this abacus, only one) the result is carried to the adjacent column to the left. The Abacus – History The abacus can be traced all the way to ancient times. ... The word Abacus is a Latin word which has its origins in the Greek words abax and abakon (meaning “table” and “tablet”, respectively), and that’s exactly what it is. ... The counting board was now evolving into something more like the modern abacus. ... When looking at the picture, one would not associate this relic with an abacus: Many cultures, in fact, have their own version of the abacus; all of them developed and evolved differently.