Select the cells or columns you want to total
Click the cell where you want the total to appear
Type `=SUM(range)` and replace `range` with your cell range
Press Enter
Repeat for each column or row you want to total
Use `=SUM(A2:A10)` for a vertical total
Use `=SUM(B2:F2)` for a horizontal total
To total an entire column, use `=SUM(A:A)`
To total an entire row, use `=SUM(2:2)`
Copy the formula to other total cells if needed
Drag the fill handle to apply totals across adjacent rows or columns
Use AutoSum from the toolbar if available
Insert a totals row at the bottom of your table
Apply the same SUM formula to each total cell in the totals row