The common way in Latex to have super- subscript is to use ^ and _ in math mode.

^ = superscript , _ = subscript , what key go back to normal ?

i tried math_failure (math_unknown_error):       also can't do it

i know now %   % store the value in the variable

what key go back to normal  ;D

i look for the answer in the net for a long time still can't find any good tips?

chance to help . thanks!