# Frequently asked questions - Math

From The Document Foundation Wiki

## How do I get * as a superscript? Using **x^*** produces an error.

The problem is that `*`

is a binary operator, which must be between two expressions. For x^{*}, use one of these sets of markup:

`x ^ { {} * {} }`

`x ^ {"*"}`

This answer applies to other binary operators such as ∙ (cdot) and ÷ (div).

Some symbols are unary operators, such as `+`

. These only require an expression on the right, not the left. To use these symbols, use one of these sets of markup:

`x^{ + {} }`

`x^{"+"}`

If you regularly use binary or unary operators as superscripts, you may want to create a userdefined symbol and then your markup would be `^ %your_symbol_name`

. See How do I use a symbol not provided in Math's Catalog of characters?