calculator

A calculator is a device that performs mathematical calculations, from simple arithmetic to complex functions. The term comes from Latin calculare, to reckon. Modern calculators range from pocket devices to software applications, and they have become common tools in education, science, engineering, finance, and daily life.

Calculating devices trace back to the abacus in ancient times, but mechanical calculators emerged in the 17th century. Blaise Pascal developed the Pascaline in 1642 for addition and subtraction, followed by Gottfried Wilhelm Leibniz's stepped reckoner in the 1690s, capable of multiplication and division. In the 19th and 20th centuries, engineers built increasingly sophisticated mechanical and electro-mechanical calculators. In the 1960s and 1970s, electronic calculators with integrated circuits reduced size and cost, enabling handheld pocket models. The first widely available handheld calculators appeared in the early 1970s, and scientific and financial models followed.

There are several categories: basic four-function calculators, scientific calculators with functions such as exponents, roots, trigonometry, and logarithms; graphing calculators capable of plotting functions and performing complex analyses; financial calculators used for interest, amortization, and cash-flow analysis; programmable calculators that can store sequences of operations or scripts. Input methods include algebraic and, in some HP-era devices, reverse Polish notation. Most calculators include memory registers, constants, and various display formats. Modern devices often combine hardware with software and may be integrated into computers and smartphones.

Calculators have transformed education, engineering, finance, and everyday tasks by enabling quick and accurate computations. They have evolved from dedicated hardware to software-based tools embedded in mobile devices, with online and cloud-based calculators expanding access. Regulations and standards govern safety, input methods, and performance in educational contexts.