CALCULATORS

A calculator is a device that performs mathematical calculations. Modern calculators are compact electronic devices with a keypad and a display, though calculators have earlier roots in mechanical devices and counting tools. They are used to perform arithmetic operations such as addition, subtraction, multiplication, and division, as well as more advanced functions depending on the model.

History of calculation devices spans from the abacus in ancient times to mechanical calculators in the 17th through 19th centuries (for example, Pascal’s calculator and Leibniz’s stepped reckoner). Electronic handheld calculators appeared in the 1960s and became widespread in the 1970s as integrated circuits reduced size and cost. Early units used simple displays and relied on batteries or solar power.

Types of calculators include basic, scientific, graphing, financial, programmable, and specialized variants. Basic calculators perform core arithmetic and percent calculations. Scientific models add trigonometric, logarithmic, exponential, and statistical functions. Graphing calculators can plot graphs and often run programs. Financial calculators include time-value-of-money tools for loans and investments. Programmable calculators allow users to write sequences of operations or small programs.

Technology and operation: Most calculators are powered by batteries or solar cells and use a microprocessor to execute firmware. They evaluate input with an arithmetic logic unit and present results in decimal form. Some employ algebraic entry, while others use reverse Polish notation (RPN). Displays are typically LCDs; input is via a numeric keypad plus function keys.

Impact and usage: Calculators are common in education, science, business, and everyday tasks. Many smartphones and computers provide calculator apps, but dedicated calculators remain popular for reliability, portability, and specialized features. Limitations include rounding errors and the absence of symbolic computation in most basic models.