Open your spreadsheet in Microsoft Excel. Click the cell where you wish the total sum to appear. Type "=SUM(range1,range2,range3)" into the cell and replace "range#" with a range of data.

The sum of the column of zeros will be displayed in the cell. Alternatively, you can type in the Sum function -- "=sum()" -- and the range to be summed if you are familiar with the Excel Sum function.