It is simply possible with childElementCount
in pure javascript
var countItems = document.getElementsByTagName("ul")[0].childElementCount;_x000D_
console.log(countItems);
_x000D_
<div id="selected">_x000D_
<ul>_x000D_
<li>29</li>_x000D_
<li>16</li>_x000D_
<li>5</li>_x000D_
<li>8</li>_x000D_
<li>10</li>_x000D_
<li>7</li>_x000D_
</ul>_x000D_
</div>
_x000D_