# Equation numbering with the same number of digits?

I'm writing a document with more than 10 equations per section. The ams align environment is numbering them as:

1.1, 1.2, ..., 1.9, 1.10, 1.11, ...

Instead I would like the equations to be numbered as:

1.01, 1.02, ..., 1.09, 1.10, 1.11, ...

How would I achieve this? Thanks.

• Welcome to TeX.SE...Can you provide a MWE, it will helps us to help you in a better way.... – MadyYuvi Aug 6 at 4:38
• \renewcommand{\theequation}{\arabic{section}.\ifnum\value{equation}<10 0\fi\number\value{equation}} – user121799 Aug 6 at 4:45
• Thankyou, that works perfectly! Sorry I didn't provide a MWE, I thought it'd be a bit tedious. – Whally Narwhal Aug 6 at 4:48

## 1 Answer

This answer is due to @user121799; that user is retiring from the site and no longer providing full answers, so I am "rescuing" their correct answer.

To add leading zeros to an equation number so that all equation numbers are the same length, redefine \theequation as follows:

\renewcommand{\theequation{%
\arabic{section}.%
\ifnum\value{equation}<10 0\fi
\number\value{equation}}