If you want to define page number format in a word document you should follow these steps;
1- Click on the Insert tab.
2- In the “Header&Footer” section part click on the Page Number.
3- Click on the “Format Page Numbers…”.
4- In the Number format part, you can specify the appearance of numbers which you want to see on your document pages.
5- If you want to show the name or number of each chapter besides the page number in the footer or header of your page, you should select “Include Chapter Number” box.
but before this step you should do the following steps;
- Specify heading in your text for each chapter;
For that, you should select each chapter in your text and then in the Style part select “Heading 1” or “Heading 2” or “Heading 3” for each heading and sub-heading part.
You can see the result of your work by following these steps;
1- Click on the View tab.
2- In the Show section select “Navigation Pan” box.
On the left side, you can see the result of your action.
Select the heading of the text.
Click on the Home tab.
In the Paragraph, section selects the Multilevel key.
Select your desired format.
you should repeat all these steps for each heading one by one.
Select the “Include chapter number” box.
In the “chapter starts with style” part choose your desired option.
Here “Heading 1” was chosen.
You can specify the separator symbol here.
In the Page numbering part, you can specify that the numbering of each section continues from the previous part or each section have their own numbering.
In the “Start at” part you can specify that the numbering of each part should start from which number.
For adding different pages number for different sections, you should do some measures before doing previous steps, for knowing those steps you can read How to Add Different Page Numbers for Different Sections article in the following link.