Go to the Tools menu, choose Options, then the View tab, and uncheck the
"Zero Values" option. This will hide ALL zero values that are the result of
a calculation. To hide zeros only on certain cells, format those cells with
the following custom number format. Note the trailing semi-colon.

General;General;

=IF(yourformula=0,"",yourformula)

e.g.   +IF(A1-B1=0,"",A1-B1)

Watch this..........0 may be just a formatting issue and you really have
0.0000000123 in the cell.

Gord Dibben  MS Excel MVP

Another way is to hide them using conditional formatting. Highlight
the cells you want to be affected in this way, then Format |
Conditional Formatting, then choose Cell Value Is, Equal To, 0 (zero),
then click the Format button and choose a foreground colour of white,
then OK twice. The cell will appear to be empty (white on white), but
the zero (and formula) is still there.

Hope this helps.

Pete