singledigit

A singledigit, or one-digit, number is a number that can be represented with a single digit in the decimal numeral system. In common mathematical usage, this refers to integers with absolute value less than 10.

In base-10 notation, the nonnegative singledigit numbers are 0 through 9. If the definition includes negative integers by magnitude, the range can be stated as -9 through 9, noting that -0 is equivalent to 0. The set of decimal digits is {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}.

One-digit numbers are fundamental to early numeracy and the decimal place-value system. They form the building blocks for larger numbers, facilitate quick mental arithmetic, and are often used in contexts where simplicity and speed are important.

In other numeral systems, the concept generalizes similarly: in base b, one-digit numbers run from 0 to b−1. Digital displays, programming, and data encoding frequently reference single-digit values as a subset of a broader numeral or data representation, especially when dealing with limited-range inputs or visual clarity.

See also: digits, place value, numeral system, arithmetic.