1. Open the form to be modified, and click the edit option at the top left of the form to enter the edit page, as shown in the figure below.

2. Find the following function options in the edit page, and click this option to enter the function page, as shown in the figure below.

3. Find the following insert option in the function page, and click this option to enter the insert page, as shown in the figure below.

4. Find the function option on the insert page, and click this option to enter the function page, as shown in the figure below.

5. Find the math and trigonometric function options on the function page, and click this option to enter the math and trigonometric function page, as shown in the figure below.

6. Find the multiplication function on the page of Mathematics and Trigonometric Function, and click the function to enter the area to insert the page, as shown in the figure below.

7. Enter the quadrature area on the area selection page, click the TAB button on the right to complete the automatic multiplication, as shown in the figure below.