# How do you number equations

I have an answer that has a number of equations. Within the text of the answer I just want to refer to the number of the equation. I saw it on an answer somewhere, but I can find such an answer now. What is the markup?

• Welcome to meta! We have a nice sandbox which is occasionally a good self-teaching guide, and almost always made dirty by our doodles. But you can find all things formatting there. – M.A.R. Nov 7 '15 at 12:26

2+2=4\tag{1}

$2+2=4\tag{1}$

• Is there a handy way to autonumber? The MathJax way I found makes things breaky -breaky. – hBy2Py Jan 11 '16 at 3:22
• Never heard of such. Maybe that's because I'm inclined to write comparatively short answers, so manual numbering would suffice. – Ivan Neretin Jan 11 '16 at 5:37