To format the "2" in m2 as superscript: On the Format menu, click Font.
Click the Font tab, and check the "Superscript" option. Click OK.
Alternatively, use the keyboard shortcut to toggle the superscript
attribute. On my system this happens to be Ctrl++, but it could be
something different for you (depending on language and probably also on
keyboard layout).
Here's how to use the Customize Keyboard dialog box to find out the
keyboard shortcut for the SuperScript command: Right-click a toolbar,
and choose Customize from the context menu. Click the Keyboard button.
Under "Categories", click "All commands". To the right, in the
"Commands" list, locate the SuperScript command and pay attention to
what it says in the "Current keys" box.