# Change equation number latex

I would like to quote a part of a paper and would like to keep the same numbering of equations. For example, suppose in a paper, the equation appears

 $$1 + 1 = 2$$


And appears numbered as (5) in the paper, and not (1) which would appear when I type it out in LaTeX. I would like to give a direct quote of the paper, including the equation number. Is there any way to do this?

• You could use \setcounter{equation}{4} to set the equation number to 5, but this will break your other numbers ;-) – user31729 Mar 17 '15 at 14:06
• Thanks, I expect only very very few equations in what I am writing. I assume I can simply use setcounter for each equation. – dblazevski Mar 17 '15 at 14:08
• You could, but it's not really nice ;-) – user31729 Mar 17 '15 at 14:09
• use amsmath, use \tag, and in the surrounding text, say something like "this is equation (5) from \cite{...}". – barbara beeton Mar 17 '15 at 14:38

You can set the number of the equations yourself with \tag and this will keep your equation numbers other than the tagged value the same. This looks odd though and perhaps isn't what you are looking for?

\documentclass{article}

\usepackage{amsmath}

\begin{document}

$$\tag{5} 1 + 1 = 2$$

$$y=mx+c$$

\end{document}

• I like this, for instance I can add some of the surrounding text and put the whole thing as a legit indented quote: \begin{quote} quoted text + equation + more quoted text \end{quote} – dblazevski Mar 17 '15 at 15:04
• This is very useful, thanks. I also realized that you can use it to repeat an earlier equation, including its number, by tagging with a ref: \tag{\ref{othereq}}. – TomasG Sep 28 '18 at 13:08
• This is documented in amsldoc, subsection 3.1. – Spherical Triangle Nov 21 '19 at 6:52