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.

  • 2
    Welcome to TeX.SE...Can you provide a MWE, it will helps us to help you in a better way....
    – MadyYuvi
    Aug 6, 2019 at 4:38
  • 8
    \renewcommand{\theequation}{\arabic{section}.\ifnum\value{equation}<10 0\fi\number\value{equation}}
    – user121799
    Aug 6, 2019 at 4:45
  • Thankyou, that works perfectly! Sorry I didn't provide a MWE, I thought it'd be a bit tedious. Aug 6, 2019 at 4:48

1 Answer 1


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:

  \ifnum\value{equation}<10 0\fi

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