JSFiddle - React, Tailwind, and code Playground

HTML

<div class="calculator" style="position:left;"> <!--calculator test-->
    <div id =a style='display:none;'>15</div>
    <div id =c style='display:none;'>20</div>
     <input id="odrasli" type="number" placeholder="Number of Adults">
     <input id="deca" type="number" placeholder="Number of Children's">

     <br />
    <button value="Submit" class="submite_btn" title="Submit" type="submit" id="get_price"><span class="">Get Price</span></button>
    <!-- <input type="button" class= "submite_btn" value="Get Price" onClick="mycalculator()">
-->
    <div id = "calcres" style="display:none;">
    <br />
 Grand total<br />
 <div id="price"></div> <div class="dolar">$</div><br />
 Deposite </br>
 <div id="depozit"></div> <div class="dolar">$</div><br />
</div>         
 </div>
         <script>

function mycalculator() {
        var a = parseInt(document.getElementById("a").innerHTML);
        var x = parseInt(document.getElementById("odrasli").value);
        var c = parseInt(document.getElementById("c").innerHTML);
        var y = parseInt(document.getElementById("deca").value);
        var aa = a * x;
        var cc = c * y;
        var p = aa + cc;
        var d = p * 0.2;
        document.getElementById("price").innerHTML = p;
        document.getElementById("depozit").innerHTML = d;
        
    }
function show() {
   document.getElementById('calcres').style.display = "block";
}
function dugme() {
   mycalculator();
   show();
}     
  document.getElementById("get_price").addEventListener("click", dugme);
         </script>