JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.0/jquery.js"></script>
<div class="notselected">TEST</div>
<div class="numadsfsaf ">TEST</div>
<div class="num-3">TEST</div>

CSS

[class^='num'] {
  color:orange;
}

JavaScript

setTimeout(function() {
  // just for demonstration a timeout - after 2 seconds the classes are removed.
  $('[class^="num"]').attr('class', function(i, val){
    return val.replace(/^num\S+/, '');
  });
}, 2000);