Each document in your book can be numbered, and these numbers can be used as automatic chapter numbers. Automatic will increment from the previous document’s number, or you can choose “Same as Previous in Book” if it’s still the same chapter but broken into two or more parts, or you can arbitrarily number it anything you want to. This can save time if you have a large number of chapters that change order frequently, since the numbers will update automatically.
In many cases, when you switch to a different numbering format, you want to restart the page numbering at the same time. To restart page numbering, position the insertion point, choose Format > Page > Numbering, and then click the Set Value button to open theValues dialog box (see Figure 3). Notice that you can use this dialog box to restart numbering for pages, chapters, volumes, and secondary pages. Type the new page number in the Set Page Number text box, and choose OK.
If you know in advance that you need outline numbering for your paragraphs, you will want to choose the correct format from the Bullets and Numbering dialog box. Applying one of the preset formats to a paragraph or paragraphs that are already bulleted or numbered applies it to the entire list. There is a specific tab for outline numbers — the Outlined Numbered tab.
You may wonder whether typing 1, 2, and 3 would be easier than using the ListNum field. Although doing that may be easier initially, the value of using the ListNum field becomes apparent when you cut and paste. When a paragraph contains multiple numbered items that you move or delete, Word automatically updates the ListNum fields. Using ListNum fields assures you of accurate numbering within a paragraph throughout the document.
Defined lists are often used to track paragraphs for numbering purposes. When you create a paragraph style for numbering, you can assign the style to a defined list, and paragraphs are numbered in that style according to where they appear in the defined list. The first paragraph to appear is given number 1 (“Table 1”), for example, and the next paragraph is given number 2 (“Table 2”), even if it appears several pages later. Because both paragraphs belong to the same defined list, they can be numbered consecutively no matter how far apart they are in the document or book.
Word's Numbering Explained by John McGhie, MVP - comprehensive and not pretty (Downloadable pdf file in letter size) - Reading this is vital to anyone attempting to use automatic numbering or bullets in a law office setting or other places where the documents are likely to be reused or heavily edited. See also How to Create a Template with a downloadable template with style-based numbering. I strongly recommend that you read both of these before doing anything with the contents of this chapter.