title: Numbered :math: equations in reStructuredText
body: <p>How can I make an equation in restructured text, that is followed by an equation number:</p>
  
  <pre><code>p = f(x)                (1)
  </code></pre>
  
  <p><p></p>
  
  <pre><code>.. math::
     p = f(x)
  </code></pre>
  
  <p>would only lead to:</p>
  
  <pre><code>p = f(x)
  </code></pre>