Siffer

Siffer is a term used in Norwegian and Danish for the symbols that compose numbers in a numeral system. A siffer, or digit, is a single graphical symbol used to represent a value in a place-value notation. In the decimal system, the ten digits 0 through 9 are used. In computing and mathematics, digits form numbers such as 2, 47, or 1024, and their meaning depends on both the digit symbols and their positions.

In computing, digits are essential for representing numerical data and for encoding values in various bases. Decimal digits are used in human-readable numbers, while binary digits (bits) are fundamental to digital electronics and data processing. Numeral systems with different bases use corresponding sets of digits, for example base-2 uses 0 and 1, base-16 uses 0–9 and A–F, and so on. The concept of digits underpins arithmetic, base conversion, and digital communication.

Etymology of the term traces to the Latin cifra, via Old French chiffre, with cognates in German Ziffer and other European languages. The English cipher shares the same root, though its modern meaning has diverged to include codes and encryption. In Scandinavian languages, siffer is widely used for digits, while in Swedish the common term for a single symbol is siffra and the plural is siffror.

See also: digit, numeral, numeral system, base, binary, decimal, code.