How do I write SI symbols in upright text in LaTeX?

[Herman Trivilino]

When I type an expression in LaTeX here in a PF post the text is always in italics. I know nothing about LaTeX but am trying to learn. How do I make the text not be in italics? I want to write SI symbols in upright text, for example.

I tried to find the answer on the web but all I could find was explanations of how to make the text be in italics!

 

[andrewkirk]

Try enclosing them in \mathrm{ }

Like this: $\sin px\ \mathrm{kg}$

##\sin px\ \mathrm{kg}##

EDIT by Jedi: Added a code block to show exactly what is typed...

 

[Herman Trivilino]

Thanks!