Actual syntax per the typography page is:
<p class="numblocks num-2"><span>here goes a number</span>and here text of element</p>
Syntax in the plug in is:
<p class="gkNumber2"><span>here goes a number</span>text of element</p>
<p class="numblocks num-2"><span>here goes a number</span>and here text of element</p>
<p class="gkNumber2"><span>here goes a number</span>text of element</p>