Plus-minus sign facts for kids

The plus-minus sign (±) is a mathematical symbol with multiple meanings.

• In mathematics, it generally indicates a choice of exactly two possible values, one of which is the negation of the other.
• In experimental sciences, the sign commonly indicates the confidence interval or error in a measurement, often the standard deviation or standard error. The sign may also represent an inclusive range of values that a reading might have.
• In engineering the sign indicates the tolerance, which is the range of values that are considered to be acceptable, safe, or which comply with some standard, or with a contract.
• In botany it is used in morphological descriptions to notate "more or less".
• In chemistry the sign is used to indicate a racemic mixture.
• In chess, the sign indicates a clear advantage for the white player; the complementary sign ∓ indicates the same advantage for the black player.

The sign is normally pronounced "plus or minus" or "plus-minus".

See also

In Spanish: ± para niños