numerical notation
Technical term used in computing and related fields for systems of representing numbers, such as binary, decimal, or hexadecimal notation.
Computers use binary numerical notation.
This textbook introduces various numerical notation systems.
Compound of 数字 (sūji, 'numeral') + 表記 (hyōki, 'notation') + 法 (hō, 'method'). A straightforward modern technical term.