Microsoft Word could insert fields that can provide automatically updated information, such as the time, title, page numbers, and so on. This tutorial will show how to insert field to inform number of pages in the document.
1. Locate pointer to desired position. Go to Insert -> Quick Parts -> Field…
2. Choose Categories: Document Information, in Field names: choose NumPages, Format: 1, 2, 3, … , and OK.
3. The field will change automatically along with the number of pages in current document. If it not change, right click on it then choose Update Field.