Instead of using the AutoSum button from the toolbar

Instead of using the AutoSum button from the toolbar,
you can press Alt and = to achieve the same result.
Try it here :
Move to a blank cell in the Total row or column, then press Alt and =.
or
Select a row, column or all cells and then press Alt and =.
Jan
Feb
Mar
Total
North
10
50
90
150
South
20
60
100
180
East
30
70
200
330
West
40
80
300
420
Total
100
260
690
1050