Numeral system in which a digit represents different values depending on the position it occupies in a number.

### Examples

In the decimal numeral system, the digit 8 occupies the tens position in the number 285; this means that it represents 8 tens, or 80 ones.

In the number 1825, the digit 8 occupies the hundreds position; it represents 8 hundreds, or 800 ones.

### Educational Note

The roman numeral system is not a positional numeral system, but it is an additive numeral system, in which every symbol has a fixed value: I, V, X, L, C, D and M representing 1, 5, 10, 50, 100, 500 and 1000 units respectively. Writing a number follows a certain number of rules that, do not apply in all cases:

XIV = X + IV = 10 + (5 – 1) = 14