=SUM formula

Step 1: Open Google Sheets and create a new spreadsheet. In the first row of the new spreadsheet, create the following column headings in cells A1 to D1 respectively: "Name", "Department", "Month", "Sales". 

Step 2: Enter the data from the table above into the corresponding cells in the spreadsheet.

Step 3: To use the =SUM formula, select an empty cell where you want the result to appear. For example, select cell E2.

Step 5: Select the range of cells that you want to sum up. In this case, select cells D2 to D10 to sum up the Sales column.

Step 6: Close the formula with a closing parenthesis ). The complete formula should look like this: =SUM(D2:D10).

Step 7: Press Enter on your keyboard to calculate the sum of Sales.

Step 8: The result will appear in the selected cell. In this case, cell E2 will display the total sales, which is 4500.

You can use this same formula to calculate the total of any column by changing the range of cells selected in step 5. Simply select the range of cells that you want to sum up and enter the formula as described in steps 4 to 6.