Barb gave you one option.
Another way would be to apply conditional formatting so that the font is
white for cells where total = 0.
Alternatively, you may need a method that allows you to show zero values
elsewhere (eg: tax).
With QTY -- Item -- Price -- Total in A1
1, try something like
=IF(COUNTA(A2:C2)3,"",A2*C2)
in D2.
Rgds,
Andy