I use LaTeX for all my physics homework and lab reports, and I’ll be using it for a master’s thesis in the next few years, so I’m constantly adding to my library of LaTeX commands to save some typing. Here’s a good one when you need to use scientific or engineering notation. Put the following in the document preamble (before \begin{document}):

\providecommand{\e}[1]{\ensuremath{\times 10^{#1}}}

Then, typing

The [111] crystal planes are 3.2\e{-10} m apart.

gives you: The [111] crystal planes are 3.2×10-10 m apart. whether or not you’re already in a math environment. If the exponent is just one number, you can omit the braces, like this: 3\e8 m/s. Cool, huh?

(Of course, for 10-10 m you can just use Angstroms, \AA. If you’re in a math environment, use \text{\AA}, or else the circle won’t line up with the A. That is, if you’re okay with non-SI units.)