Press Ctrl+C. Press Esc. Select the destination cell, F3, and press Ctrl+V. As you can see in the data set to the right in Figure A, both expressions reference the same cells, B3 and C3.

Doing this tells Excel to add the June and July cell values to create a total. When people view the Total worksheet, they will see total sales for June and July in the worksheet's B1 cell.