If you have a lot of cells to check, that's going to take you a while. If you want to check your work, you can always click on a cell to see the formula behind the cell's value it will be displayed in the formula bar, between the ribbon and the worksheet. The default display mode in Excel shows you the results of formulas, so a column of sales figures ends in your total sales for the month, not a truncated formula beginning =SUM(D2.
