text: // Business (or back-end) logic:
  
  var add = function(num1, num2){
  return num1 + num2;
  };
  
  var subtract = function(num1, num2) {
    return num1 - num2;
  }
  var divide = function(num1, num2) {
    return num1 / num2;
  }
  
  var multiply = function(num1, num2) {
    return num1 * num2;
  }
  
  
  // Everything below this line is user interface (or front-end) logic:
  $(document).ready(function() {
    $("form#add").submit(function(event) {
      event.preventDefault();
      var num1 = parseInt($("#add1").val());
      var num2 = parseInt($("#add2").val());
      var result = add(num1, num2);
      $(".output1").text(result);
  
    });
  
    $("form#subtract").submit(function(event) {
      event.preventDefault();
      var num1 = parseInt($("#sub1").val());
      var num2 = parseInt($("#sub2").val());
      var result = subtract(num1, num2);
      $(".output2").text(result);
  
    });
  
    $("form#multiply").submit(function(event) {
      event.preventDefault();
      var num1 = parseInt($("#mult1").val());
      var num2 = parseInt($("#mult2").val());
      var result = multiply(num1, num2);
      $(".output3").text(result);
  
    });
  
    $("form#divide").submit(function(event) {
      event.preventDefault();
      var num1 = parseInt($("#divide1").val());
      var num2 = parseInt($("#divide2").val());
      var result = divide(num1, num2);
      $(".output4").text(result);
    });
  });
  