You can show rulers to help you position and align objects, and hide the rulers when you don’t need them.
Click 
in the toolbar, then choose Show Rulers or Hide Rulers.
To show size and position coordinates when moving objects, choose Numbers > Preferences (from the Numbers menu at the top of your screen), then click Rulers. Select the “Show size and position coordinates when moving objects” checkbox.
When you set a unit preference for rulers, it applies to all sheets. You can change the preference at any time, even if you have a sheet open.
If you don’t see the ruler, click in the toolbar, then choose Show Ruler.
Choose Numbers > Preferences (from the Numbers menu at the top of your screen), then click Rulers at the top of the preferences window.
Click the Ruler Units pop-up menu, then choose an increment (Points, Centimeters, or Inches).