Basnummer

Basnummer, in mathematics and computing, refers to the base or radix of a numeral system—the number of distinct digits used and the weighting of digits in positional notation. In a base-n system, a number is expressed as a sum of digits times n raised to successive powers. The concept underpins how numbers are represented in different numeral systems.

Common bases include decimal (base-10), which uses digits 0 through 9; binary (base-2), which uses 0 and 1; and hexadecimal (base-16), which uses 0–9 and letters A–F. Other widely used bases include octal (base-8) and base-36 (0–9 and A–Z). Some specialized systems, such as sexagesimal (base-60), appear in areas like timekeeping and angular measurements. In formal contexts, the base can sometimes be any integer greater than or equal to 2.

Numbers are written with a base indicator when clarity is needed, for example 1011_2 for binary or 1A_16 for hexadecimal. In decimal, 345 equals 3×10^2 + 4×10^1 + 5×10^0. Converting between bases can be done by repeated division by the target base for the integer part and repeated multiplication for fractional parts, or by converting through an intermediate base such as base-10 or base-2.

Basnummer is central to computer science and digital electronics, where data are stored and processed primarily in binary, and to various encoding schemes and communication protocols that rely on different base representations. The term is often used interchangeably with radix in mathematical contexts.