First, for example, if you want to hit five square meters, then enter "5m" first.
Second, then switch to the QQ five-stroke input method, right-click the keyboard on the input method status bar, and click the symbol input device in the right-click menu.
3. Enter the special symbol-number/unit, find the superscript number 2, and then click Enter.
4. As shown in the figure below, you can enter the superscript number 2 after m at this time.