# Positional Notation – IP addresses

Learning to convert binary to decimal requires an understanding of *positional notation*. **Positional notation** or place-value **notation** is a method of representing or encoding numbers. **Positional notation** is distinguished from other **notations**. Positional notation means that a digit represents different values depending on the “position” the digit occupies in the sequence of numbers. You already know the most common numbering system, the decimal (base 10) notation system.

### Radix

The first row identifies the number base or radix. The decimal notation system is based on 10, therefore the radix is 10.

### Position in number

The 2nd row considers the position of the decimal number starting with, from right to left, 0 (1st position), 1 (2nd position), 2 (3rd position), 3 (4th position). These numbers also represent the exponential value that will be used to calculate the positional value (4th row).

### Calculate

The 3rd row calculates the positional value by taking the radix and raising it by the exponential value of its position. Note: n^0 is always = 1.

### Positional Value

The first row identifies the number base or radix. Therefore the value listed, from left to right, represents units of thousands, hundreds, tens, and ones.