Used in mathematics and computing to refer to the base of a numeral system, such as 10進数 (decimal) or 2進数 (binary).
Computers calculate in binary (base 2).
The decimal system (base 10) is the most commonly used in daily life.
binary digits; binary number
octal number; base-8 number
decimal number; decimal digit
binary coded decimal; BCD
Compound of 進 (advance, proceed) and 数 (number). The exact historical derivation is uncertain, but the term is used in modern Japanese to denote the base of a numeral system.