You can insert a page using +/- menu in the book builder (see below). There are several options for doing this. You can add two pages (a sheet) at the current location. In the example below you see pages 6-7. "Add 2 Pages" will insert two blank pages as pages 6-7. The yellow flower page will become page 8. You can also "Add Left Page" or "Add Right Page." These will insert a blank page as page 6 or 7 respectively, and add a blank page at the end of the book. This is because when you add a page, you're adding a sheet (two pages). You cannot add a single page to a physical book. So we add the second page to the end of the book.
Select "Delete Page" from +/- menu in book builder. See the image below. This deletes the current page (page number highlighted in blue), and the book pages shift left by one position, resulting in a blank page at the end of the book. Note that the first time you delete a page it will not reduce the number of pages. This is because you can only delete a sheet (two pages) from a physical book. The subsequent time you delete a page, it will reduce the number of pages in the book by two. This is because when you delete a single page the number of sheets in the page remains the same but if you delete two pages in a row, then a single sheet is removed. Also keep in mind that our photo books require a minimum of 20 pages. So you cannot delete pages if the book has 20 pages.