1. Turn on the computer and enter the desktop, then open the word document. Enter the upper and lower numbers in the document first, then find the paragraph tab in the start menu, and then click the paragraph tab. There is a symbol in Chinese format in the paragraph.

2. Click on the drop-down menu of Chinese format symbols to see a double-line fusion option, and click to select the double-line fusion option.

3. A two-line dialog box appears, with a text editing box above, where you can enter a small label, and a preview box below. After input, you can preview the box below, enter a subscript in the text editing box, and leave a space between them. After entering, click OK in the lower right corner, and then return to the word document.