This issue was replicated on the trunk version of MediaWiki with the trunk version of Math.

When including a template that contains a <div> tag on an article that contains a <math> tag, the <p> paragraph tags are dropped around some surrounding text. Since this is hard to explain, I will show my test pages:

http://104.131.177.223/mediawiki/index.php/Math_Test
http://104.131.177.223/mediawiki/index.php/Math_Test_2

Why this is a problem:

At wikiHow, my current employer, a library called phpquery is used to re-arrange and wrap elements in the article to match up with our skin. When the <p> tag is lost, the text ends up outside our introduction section div, forcing us to use a workaround to get the style back (like manually surrounding the text only with <p> (the template can not be in the paragraph tag). I do not know enough about MediaWiki and Math's internal parser to think of a patch right away.

wikiHow production example: https://www.wikihow.com/index.php?title=Calculate-Bond-Value&diff=prev&oldid=19709660