title: Angular2 Error: Type 'number' is not assignable to type 'NumberConstructor'
body: <p>In the following Angular2 program where I want the system to randomly choose four choices from either 0 or 1. I'm getting the desired output and the console doesn't report any error. However, my IDE displays the following error:</p>
  
  <p><a href="https://i.stack.imgur.com/AosIk.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AosIk.png" alt="Angular2 Error"></a></p>
  
  <p>I tried changing <code>Number</code> to <code>number</code> but it yields another error:</p>
  
  <p><a href="https://i.stack.imgur.com/RhplA.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/RhplA.png" alt="Another Error"></a></p>
  
  <p><strong>Component Code</strong></p>
  
  <pre><code>import {Component} from 'angular2/core';
  import {OnInit} from 'angular2/core';
  
  @Component(
  {
      selector: 'puzzle',
      template: `
          &lt;section class="combination"&gt;
              I:   {{ switch1Number }}&lt;br&gt;
              II:  {{ switch2Number }}&lt;br&gt;
              III: {{ switch3Number }}&lt;br&gt;
              IV:  {{ switch4Number }}
          &lt;/section&gt;
      `
  })
  
  export class PuzzleComponent implements OnInit {
      switch1Number = Number;
      switch2Number = Number;
      switch3Number = Number;
      switch4Number = Number;
  
      ngOnInit() {
          // Math.randon gives a random decimal value between 0 &amp; 1.
          // Math..round rounds it to 0 or 1
          this.switch1Number = Math.round(Math.random());
          this.switch2Number = Math.round(Math.random());
          this.switch3Number = Math.round(Math.random());
          this.switch4Number = Math.round(Math.random());
  
          console.log(this.switch1Number, this.switch2Number, this.switch3Number, this.switch4Number);
      }
  }
  </code></pre>