You could just use a text-version of "`tt`

", called `\texttt`

:

```
\documentclass{article}
\begin{document}
\[
\texttt{<trigger threshold>} = \mathrm{average} - (\texttt{<trigger fraction>} \times \mathrm{average})
\]
\end{document}
```

In the above example I've included both, just to show you that you can mix and match what you want. However, if you're interested in such things on a more global scale, it's best to define something like

```
\newcommand{\variable}{\texttt}% or \newcommand{\variable}[1]{\texttt{#1}}
```

and then use

```
\variable{<trigger threshold>} = \mathrm{average} - (\variable{<trigger fraction>} \times \mathrm{average})
```

See Consistent typography. If you're not using a macro-form, a plain short-hand `\verb`

also suffices.

You surely can define your shortcuts; indeed you *should*.

Let's make some examples. Suppose your document is full of Fourier transforms, for which you need a fancy F. Instead of writing every time

```
$\mathcal{F}(f)$
```

it's surely better to define a new command, say

```
\newcommand{\FT}{\mathcal{F}}
```

(choose any name you like), so that you can type

```
$\FT(f)$
```

and get the same result as before, with a big bonus! If you change your mind about the notation, you can simply modify the definition.

Another example. The "gradient" operator is not predefined; so you might want to have a command for it:

```
\DeclareMathOperator{\grad}{grad}
```

A different one; my preferred notation for vectors is, say, `\mathbf{v}`

. However, since conventions are different, I never type vectors in that way, but prefer to have

```
\newcommand{\vect}[1]{\mathbf{#1}}
```

for the same reason as before; I might change my mind and want to modify the appearance, say for using bold italic; this would be accomplished just by saying

```
\usepackage{bm}
```

and changing the above into

```
\newcommand{\vect}[1]{\bm{#1}}
```

How do you organize this? Here's an example:

```
\documentclass[a4paper]{book}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc} % input encoding UTF-8
% Useful packages
\usepackage{amsmath,amssymb,amsthm}
% add all the packages you need
% Personal definitions
\newcommand{\FT}{\mathcal{F}} % Fourier transform operator
\DeclareMathOperator{\grad}{grad} % gradient
\newcommand{\vect}[1]{\mathbf{#1}} % vectors and matrices
\begin{document}
...
\end{document}
```

Add definitions while you find that they are useful for distinguishing logical units of your document.

## Best Answer

There are online tables for symbols that you can use to add math symbols, just copy and past from them into your documents.There is also this keyboard for writing math symbols and equations.