Using the Subtotal feature in Excel2013

1. Open a worksheet with Excel2013, select the worksheet area that you want to subtotal, and then switch to the Data tab and click the Filter button.

2, now each column of the field name on the right side will appear a Drop-down button, we click the "elective course" to the right of the Drop-down button, and then from the pop-up dialog box to select the "Ascending" option.

3. At this point, the entire table will be categorized according to different elective courses, and we perform the subtotals command in the outline group.

4. In the Pop-up Subtotals dialog box, we first click the button to the right of the Category field dropdown box and select the elective course item.

5, then, we modify the summary method. Click the Summary drop-down box to have a side button and select the average option.

6. Now, we check the "score" item in the "Selected totals" area, and then click the OK button.

7, return to the worksheet, you can see that it has been in accordance with our intention to sum up, and is the outline, the left side of the display series.