Angular JS - Exposing Controller Function outside the module via onClick function call

Exposing Controller Function outside the module via onClick function call For re-using already defined onClick functions

HTML

<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css">
<div ng-app="demo">
        <div ng-controller="democtr">
            <p> add js value together: {{a}} +{{b}} ={{a + b}}</p>
            <input type="number" ng-model="a">
            <input type="number" ng-model="b">
        </div>
        <div ng-controller="democtr">
            <p> add js value together: {{a}} +{{b}} ={{a + b}}</p>
            <input type="text" ng-model="a">
            <input type="text" ng-model="b">
        </div>
    </div>

JavaScript

angular.module('demo', [])
       .controller('democtr', function($scope) {
         $scope.a = 1;
         $scope.b = 2;
       });