Calculator

Calculator A calculator is a small (often pocket-sized), usually

inexpensive electronic device used to perform the basic operations of arithmetic. Modern calculators are more portable than most computers, though most PDAs are comparable in size to handheld calculators.

The calculator has its history in mechanical devices such as the abacus and slide rule. In the past, mechanical clerical aids such as abaci , comptometers, Napier's bones, books of mathematical tables, slide rules, or mechanical adding machines were used for numeric work. This semi-manual process of calculation was tedious and error-prone. The first digital mechanical calculator was invented in 1623 and the first commercially successful device was produced in 1820. The 19th and early 20th centuries saw improvements to the mechanical design, in parallel with analog computers; the first digital electronic calculators were created in the 1960s, with pocket-sized devices becoming available in the 1970s.

Calculator Modern calculators are electrically powered (usually

by battery and/or solar cell) and vary from cheap, give-away, credit-card sized models to sturdy adding machine-like models with built-in printers. They first became popular in the late 1960s as decreasing size and cost of electronics made possible devices for calculations, avoiding the use of scarce and expensive computer resources. By the 1980s, calculator prices had reduced to a point where a basic calculator was affordable to most. By the 1990s they had become common in math classes in schools, with the idea that students could be freed from basic calculations and focus on the concepts.

Calculator

Calculator In addition to general purpose calculators, there

are those designed for specific markets; for example, there are scientific calculators which focus on operations slightly more complex than those specific to arithmetic – for instance, trigonometric and statistical calculations. Some calculators even have the ability to do computer algebra. Graphing calculators can be used to graph functions defined on the real line, or higher dimensional Euclidean space. They often serve other purposes

Design Modern electronic calculators contain a keyboard

with buttons for digits and arithmetical operations. Some even contain 00 and 000 buttons to make large numbers easier to enter.

Fractions such as 1⁄3 are displayed as decimal approximations, for example rounded to 0.33333333. Also, some fractions such as 1⁄7 which is0.14285714285714 (to fourteen significant figures) can be difficult to recognize in decimal form; as a result, many scientific calculators are able to work invulgar fractions and/or mixed numbers.

Scientific calculator displays of fractions and decimal equivalent

The fundamental difference between a calculator and computer is that a computer can be programmed in a way that allows the program to take different branches according to intermediate results, while calculators are pre-designed with specific functions such as addition, multiplication, and logarithms built in. The distinction is not clear-cut: some devices classed as programmable calculators have programming functionality.