Open "task1" which you created in the previous exercise. Enter a formula in cell F3 which will add up the numbers in cells B3, C3, D3 and D3.  Remember to use the SUM formula, just as in the example. Now do the same for cell F4 and F5 When you have completed this, enter formulae in cells B6, C6, D6 and E6 which add up the numbers in the columns above them. Save this spreadsheet at "task2" in your "Excel" folder.