Windows7 + Office '07

I am okay with Excel formulas and the associated procedures but do not get how Word handles same within a table. When you click on formulas on the ribbon and the box appears with an '=' sign waiting for the user to instruct, help is no virtually no help (why am I not surprised). Plus, one cannot (with that box open) cursor from one table cell to another adding the appropriate math symbol (+, *, etc) along the way?


Mark