In a previous post (Typesetting text in math mode) I advertised the use of `\mbox`

to write text in mathematical formulas. This works when you are in the "standard size", but looks funny if you have subscripts because the sizes are off:

$ 50 \mbox{ apples}_{\mbox{yellow}} \times 100 \mbox{ apples}_{\mbox{red-green}} = \mbox{lots of apples}^{\mbox{to eat}} $

looks like

In these cases (and also in the standard cases but there it looks the same), you can use the command `\text`

which will come out in the right font size. In addition to just `\text`

, there is also `\textbf`

(bold face), `\textit`

(italics) and `\texttt`

(typewriter).

$ 50 \text{ apples}_{\text{yellow}} \times 100 \textit{ apples}_{\texttt{red-green}} = \textbf{lots of apples}^\text{to eat} $

looks like

Note: Most of the time `\text`

should just work in math mode without any packages, but for some distributions you need to explicitly load the package amstext or amsmath.