JSFiddle - React, Tailwind, and code Playground

HTML

<input  value="0.99" type="checkbox">
<input  value="0.99" type="checkbox">
<input  value="0.99" type="checkbox">
<input  value="0.99" type="checkbox">
<input  value="0.99" type="checkbox">

JavaScript

var pizzaCost = 0.00;
var toppingCost = 0.00;

$('input[type=checkbox]').change(function(){
    var checked = $(":checkbox:checked").length;
    var checkedInt = parseFloat(checked, 10);
    var temp = (0.99 *100* checkedInt);
    toppingCost = parseFloat(temp)/100;
    var total = pizzaCost + toppingCost;
  console.log(toppingCost);
    $("#totalPrice").text(total);
});