A place value system is a number system in which each digit of a number is assigned a valence. The different binary codes usually have different place values. For example, the BCD code has the valence 8-4-2-1, the Aiken code 2-4-2-1.
This is illustrated by the example of a decimal number. In the number 4321, the digits 4, 3, 2 and 1 each represent a valence of their own, independent of the order of the sequence. In the sequence, however, the digits represent a valence. The first digit, occupied by the "4" represents thousand, the second digit with the "3" represents the place value hundred, the third (2) represents ten and the last one represents one.
This place value system is generally used in the representation of natural numbers, equally in the dual system, binary system, octal system, decimal system and hexadecimal system and enables the calculation with numbers.