Calculator

Modern electronic calculators are small (often pocket-sized), digital, and usually inexpensive devices to perform the basic operations of arithmetic. In addition to general purpose calculators, there are those designed for specific markets; for example, there are scientific calculators which

A scientific calculator.

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

An old mechanical calculator.

dimensional Euclidean space. They often serve other purposes, however. Modern calculators are more portable than most computers, though most PDAs are comparable in size to handheld calculators.