I think you meant positional number system or Positional Notation. In computer science when we talk about positional notation where talking about the binary(base 2) and hexadecimal(base 16) system.

So for the most part a positional number system is a counting system. We for example use a base 10 counting system.

It's a yes or no question

Base-10 decimal positional notation.

The operations are the same as in decimal (+ - / x) the positional notation is somewhat different.

We use Positional notation,

0.45 = 4 / 10 + 5 / 100

0.54 = 5 / 10 + 4 / 100

Therefore 0.54 is larger.