How to get rid of lettering in the sectioning?

Question

Using article class, and I wonder how do i change sectioning from letters to numbers? (pic attached). Preferable to have sections as integers, and subsections as 1.1 , 1.1.1 etc... if section is 1. (so 1 instead of A. in the picture)

Similar code for a different article generates roman numerals, so not sure what's at play here. But I wonder if numbering from ijmart class is possible to do in article class in short.

Answer 1

\renewcommand\thesection{\arabic{section}} should do the trick. In order to change the subsection format, do \renewcommand\thesubsection{\arabic{subsection}} and so on.

From what I know, article class has arabic enumerations set as standard, though. Mind sharing a reproducible example if the above lines don't fix the issue?