Select the cell where you want the total to appear
Type `=SUM(`
Select the range of cells you want to add
Type `)`
Press Enter
Use `=SUM(A1:A10)` to add a continuous range
Use `=SUM(A1,A3,A5)` to add non-adjacent cells
Use `=SUM(A1:A5,B1:B5)` to add multiple ranges
Use AutoSum by selecting the total cell and pressing `Alt` + `=`
Include additional ranges or cells inside the SUM formula as needed