These operations are available only in Symbol Mode Math entry.
The basic formula entry cell for Symbol Mode resembles the following when it appears in a question.

Math expressions and equations are created from palettes.
To display palettes, right-click (Control-click on Macintosh) in the Equation Editor.
Highlight and click a symbol. The symbol is displayed in the Equation Editor.
If necessary, use the arrow keys to move between placeholders. For more information, see Entering and Editing Formulas in Symbol Mode.