<!doctype html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Example - example-guide-concepts-1-production</title>
  

  <script src="//code.angularjs.org/snapshot/angular.min.js"></script>
  

  
</head>
<body >
  <div ng-app ng-init="qty=1;cost=2">
  <b>Invoice:</b>
  <div>
    Quantity: <input type="number" min="0" ng-model="qty">
  </div>
  <div>
    Costs: <input type="number" min="0" ng-model="cost">
  </div>
  <div>
    <b>Total:</b> {{qty * cost | currency}}
  </div>
</div>
</body>
</html>