If you have a multipage document that is need of page numbers, Pages for iPad makes it easy and automatic. You just to to find and set the desired style and location and Pages will do the rest.
1. Open the desired document.
2. Go to the toolbar and tap the Tools icon. When the menu appears, select Document Setup.
3. Select either Tap to edit header (at the top) or Tap to edit footer (at the bottom), depending on where you want the page numbers located.
4. Select the desired region, (left, center, or right) where you want the page number located.
5. Go to the upper right corner of the page and tap the # icon.
6. Select the desired page numbering style.
7. Tap the Done button in the upper left corner.