minus

The minus is a symbol used in mathematics and related fields to indicate subtraction and negation. It also functions as a sign for negative quantities or values, as in minus five or temperatures below zero. In everyday writing, the word minus may be used in phrases like “three minus one.”

Symbol, typography, and encoding: The formal minus sign is the Unicode character U+2212 (−). In plain text and many keyboards, the hyphen-minus character (U+002D, the same symbol used for hyphen and minus in ASCII) is frequently used as a stand‑in for a minus, which can lead to typographic inconsistencies. Distinct typographic marks include the hyphen (shorter), the minus sign (longer and centered vertically), the en dash, and the em dash, each with different conventional uses.

Mathematical use: In arithmetic, the minus sign denotes subtraction between two numbers or expressions. It also serves as unary negation, indicating the additive inverse of a number (for example, −7 is the negation of 7). Subtraction is not commutative, whereas negation is a unary operation that reverses the sign of a number.

Computing and programming: In most programming languages, the minus operator supports binary subtraction (a − b) and unary negation (−a). Precedence rules determine how expressions are grouped, and the operator may interact with other operators. Examples include 5 − 3 = 2 and −7 written as a single token in languages that support unary minus.

Etymology and overview: The term minus comes from the Latin word minus meaning “less.” The symbol’s precise typographic form and usage have varied historically, but its functional role as a binary operator for subtraction and a unary operator for negation remains central in mathematics, science, and computer science.