Finding what makes up a summed cell in Excel
 

If I have a number of spreadsheets I am summing together, I use the formula that will sum the same cell on a range of tabs. Some of those tabs may not have any data in the cell I am summing. From the sum formula, is there a way to find out which tabs do have data that make up the sum without having to manually go through each tab?

Thanks for any help you can provide!