title: Increment of input type number appending number instead of incrementing
body: <p>During the first time, it's incrementing correctly. However, using arrows if the values are changed, then the button increment is appending text instead of incrementing it.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>var visits = 100;
  
  function incrementStep(data) {
    visits = visits + data;
    $('#visits').val(visits);
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"&gt;&lt;/script&gt;
  &lt;input type="number" id="visits" value="100" step="100"&gt;
  &lt;span onclick="incrementStep(500)"&gt;500&lt;/span&gt;</code></pre>
  </div>
  </div>
  </p>