Microsoft Excel. Help With Hiding Zeros.

So I just started using Microsoft Excel 2013. I have a column of sums taken from 2 other columns. Like this C4=A4-B4 and C5=A5-B5. Even though the blocks in the A and B column are empty it is still calculating it and returning a 0, but that's not the exact problem. After some googling I quickly found multiple ways to hide zeros, and here's where the problem is. They also hide the zero when there IS something present in the A/B squares. For instance, if A4-B4 is 4-4 then C4 would be 0, but it shows as a blank square.

TL;DR: Is there way to hide a 0 when the blocks in a sum are blank, but show the zeros if there is an actual calculation present.

if there's nothing to calculate in that field, why have something calculate it?

=IF(AND(A4="",B4="")=TRUE, "", A4-B4)

It's a sheet for sales and I'm trying to set up all the cells for someone else. The columns are Price, Start Amount, Amount Sold, End Amount, and Total. Then a Total Daily Sales number below the total column.

I have it set so Price x Amount Sold = Total, Start Amount - Amount Sold = End Amount, and the sum of the Total column is added up in to the Total Daily Sales cell.

I set it up so this person could just key in the numbers for the amount of product they started the day with, and the numbers for amount sold and the rest would get calculated on it's own.

I just hate the fact that the entire End Amount column is all zeros even when there's nothing keyed into Start amount and Amount sold fields. I tried to fix it but like said, if they would key in numbers that equal 0, it would be a blank space as well and I didn't want that either.

ah, well what that guy posted does work

Thanks man ^^, that worked.