JSFiddle - React, Tailwind, and code Playground

HTML

<span style="font-size:20px;">Your bid:</span> 
<input type="number" id="bid" class="form-control" style="max-width:250px; margin-top:10px;" onkeyup="cal()">
<br>
<span style="font-size:20px;" >Our Fee (10%):</span>
<input type="number" id="fee" readonly class="form-control" style="max-width:250px; margin-top:10px;">
<br>
<span style="font-size:20px;">You'll paid:</span>
<input type="number"  id="get" readonly class="form-control" style="max-width:250px; margin-top:10px;">

JavaScript

function cal(){
  var bid = Number(document.querySelector("#bid").value);
  var result1 = bid * 0.1;
  var result2 = bid - result1;
  document.querySelector("#fee").value = result1;
  document.querySelector("#get").value = result2;
}