JSFiddle - React, Tailwind, and code Playground

HTML

<div class="myCaolc">
  <form action="">
  <label for="sum">Сумма</label>
    <input type="text" id="sum"> <br/>
    <label for="summa">Ваш процент</label>
    <input type="text"  id="percent">
     <br/> <br/>
    <input type="submit" id="calc" value="Посчитать">
  </form>
  
  <p id="contenInput"></p>
  
</div>

CSS

input[type="text"]{
  margin-bottom: 10px;
}

JavaScript

$(document).ready( function(){

	$("#calc").click(function () {
  	
    
   
    
    var x= Number($("#sum").val()),
    		y = Number($("#percent").val()),
        z = x + (x*y*0.01);
    
    $('#contenInput').text(z);
    
   
    
    return false;    
    });






});