Currently Being ModeratedJan 18, 2013 1:56 PM (in response to harmswor)
you can refer directly to another cell in aother table (in the same or a different sheet... all in the same document). To do that you can type the "=" in the destination cell, then navigate by clicking on sheet names, and table names, then click the cell you want to refer to.
the baset way to start if to download, and review, the free Numbers Users Guide:
If you have a particular problem, can you post that question?