the method of denoting numbers by the use of a finite number of digits, each digit having its value multiplied by its place value, as in 936 = (9 × 100) + (3 × 10) + 6
positional notation in American English
noun
a type of numeration in which the position of a digit affects its value
Word origin
[1940–45]This word is first recorded in the period 1940–45. Other words that entered Englishat around the same time include: black box, blockbuster, silkscreen, snorkel, whiteout