positional notation; positional representation system
Computing term for a numeral system where a digit's position determines its value (e.g., decimal, binary).
Computers handle numbers using positional notation.
位取り記数法 is a more common synonym for positional notation; 位取り表現法 is less frequent but used in some computing contexts.
Compound of 位取り (くらいどり, 'place assignment') + 表現法 (ひょうげんほう, 'representation method').