excel object linked to word will not add sums in word
 

I have created a summation table in excel. Have linked it to word. It(object
in word) automatically updates the sum when I change it in excel; however, it
will not update the sum if I change the cells that should change the sum cell
in word. I have followed instuctions for manual update and by double clicking
in the excel object in word but it will not automatically update the sum cell.