title: show discount percent of product in Text Widget in flutter
body: <p>I want to show amount of discount percent in Text widget in flutter, i used the Discount calculation formula but it didn't worked , How can i do that?
  this is what i want:</p>
  
  <pre><code>Container(
    decoration: BoxDecoration(
    color: Color(0xfff40725),
    borderRadius: BorderRadius.circular(50),
  ),
  
  child: Padding(
    padding: const EdgeInsets.all(5.0),
    child: Text(
      '50% (but with formula',
      style: TextStyle(
        color: Colors.white, 
        fontWeight: FontWeight.bold),
      ),
    ),
  ),
  </code></pre>