There are LOTS of P tags. Every single paragraph in the post is wrapped in P tags. Go to your page in a browser and view the source. Below is an excerpt...
<p>Commonly, someone I am helping will ask, ” But what if we are not allowed to do it that way?” Recently someone wrote in:</p>
<blockquote><p>“I am fascinated with your approach to math but worry about teaching these kids differently from what their
The WordPress editor can be a bit tricky. When you switch to HTML mode, it hides the <p> tags and puts in blank lines. If you are typing out the more tag in the editor, be sure there are no blank lines before or after the tag. If you've done it correctly, when you go back into visual mode, you'll see a horizontal line at the break point.
It may be easier for you to use the more button in visual mode rather than typing it out. Just put the cursor where you want the break and click the more button at the top of the editor window. (It's the button right before the spell check button.) It will put the more tag in correctly.