Using AutoSum for Quick Calculations in Excel 2007
To quickly sum a row or a column of values in an Excel 2007 worksheet, you can use the AutoSum button (the one with the on it) in the Editing group of the Home tab of the Ribbon. When you click this button, Excel inserts the built-in SUM function into the active cell and simultaneously selects what the program thinks is the most likely range of numbers that you want summed.
1Click a cell below (or to the right of) the values you want to sum.
This tells Excel which values you want to sum.
2Click the AutoSum button in the Editing group on the Home tab.
Excel inserts an equal sign followed by the SUM function and a suggested range of values to sum displayed in a marquee.
3If the suggested range is incorrect, drag the cell cursor across the cells to select the correct range.
The marquee adjusts to surround the range of cells you select.