Add all continuous numbers of a column or row.

 In a worksheet enter a formula that uses the SUM function (also known as AutoSum) to quickly total a series of values without spending time to manually enter each cell.

Image 1

In the cell where you want the total of the column, write "= sum ". Then click on the first number cell that you want to add ( as shown in Image 1), drag the cursor to the last cell of which you want the total and close it with a bracket ( as shown in Image 2). Press Enter.

Image 2

The sum is shown in the total column and if you want to look at the formula later, it is shown in the formula bar in the upper side of the screen ( refer to Image 3).                                                                              

( click on the images to enlarge it )