Use the Number tool to represent a tag or expression as a number. When you place a number on your page, simply enter the relevant variable tag or expression. Numbers can be moved, resized, brought to the front, and so on, and their properties edited just like other types of object.
(The same functionality is also available through the Text tool.)
To add a number to your graphics page:
For help on the various Properties tabs, see Text Properties - Appearance (General) and Defining Common Object Properties.