Adding Column Totals

Here we will add a total to the bottom of both columns A and B, and then make these a black background colour and with white foreground

1. On the bottom of your table (row 21), select both A21 and B21 cells**, then add column totals using the sum icon found on the Home ribbon

\ left mouse click on A21 and while keeping the mouse button clicked-down, drag to B21 - then release\*
*** You can also use the [SHIFT] or [CONTROL] keyboard buttons to multi-select cells similar to Step 2.

2. Now with the same cells still selected, you can mouse right-button click and select Format Cells... [Font tab, and Fill tab] or use the Home ribbon options to change the cell backgrounds to black, and the foregrounds to white

Background Notes

This SUM icon has actually placed a formula =SUM(A1:A20) into each of your selected cells

Formulas can be seen using the leading = sign convention in a cell. If a cell starts with = then the formula is calculated, otherwise the value is just shown

For example 1 * 2 in a cell with read just that, but =1 * 2 will evaluate and show as 2 on the grid (with the original formula still visible and editable in the Formula Bar field at the top of the worksheet.