text: // Javascript Evenets:
  // - click
  // - mouseenter
  // - mouseleave
  // - mousedown
  // - mouseup
  // - mousemove
  // - keydown
  // - keyup
  // - blur
  // - focus
  
  var numOne = document.getElementById("num-one");
  var numOne = document.getElementById("num-two");
  var numOne = document.getElementById("add-sum");
  
  numOne.addEventListener("input", add);
  numTwo.addEventListener("input", add);
  
  function add() {
              // number               if none put 0
    var one = parseFloat(numOne.value) || 0;
    var two = parseFloat(numTwo.value) || 0;
    var sum = one + two;
    addSum.innerHTML = "your sum is:" + sum;
    addSum.innerHTML = "your sum is:" + (one + two); // other way
    console.log(one, two);
  }
  