rec-approx1

22/7 is approximately pi

W3C sample	WIRIS
	$22 7 π$

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <apply>
    <approx/>
    <cn type="rational">22
      <sep/> 7
    </cn>
    <cn type="constant"> &#x003C0;</cn>
  </apply>
</math>

Author: MathML 2 Recommendation