title: TypeScript additionning number return high float
body: <p>I've an issue with TypeScript. When i addition two number (<em>15.99</em> and <em>5.00</em>)
  i get <em>20.9900000000002</em> in result.</p>
  
  <p>Here my declaration :</p>
  
  <pre><code> private difference: number;
   private prixReference : number;
   private max: number;
  [...]
   this.prixReference = 15.99;
   this.difference = 5.00;
   this.max = this.prixReference + this.difference;
  </code></pre>
  
  <p><strong>Debugger</strong> :</p>
  
  <p><a href="https://i.stack.imgur.com/EAz7p.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EAz7p.png" alt="debugger values"></a></p>
  
  <p>Any idea ?</p>