我有使用angular js的代码:
<!DOCTYPE html >
<html>
<head>
    <title>Untitled Page</title>
    <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.5/angular.min.js"></script>
    <script type="text/javascript">
        function TodoCtrl($scope) {
            $scope.total = function () {
                return $scope.x + $scope.y;
            };
        }
    </script>
</head>
<body>
   <div ng-app>
  <h2>Calculate</h2>
  <div ng-controller="TodoCtrl">
    <form>
        <li>Number 1: <input type="text" ng-model="x" /> </li>
        <li>Number 2: <input type="text" ng-model="y" /> </li>
        <li>Total <input type="text" value="{{total()}}"/></li>       
    </form>
  </div>
</div>
</body>
</html>
我能够进行乘法,除法和减法但是为了加法,代码只是连接x和y值(即如果x = 3且y = 4,则总数为34而不是7)
我究竟做错了什么?