title: Angular 7 Reactive Form Array - Calculate Form values
body: <p>I have been creating a billing application where I will be capturing item name and price. I want to give discount for the item so I will be having discount in percentage and discount in dollar text boxes. In some cases, either I can enter discount in percentage or discount in dollar values so I want to display both of the them at run time. For example, if I enter discount in dollar then I have to display value in discount in percentage. Can you please help me to solve the requirement?      </p>
  
  <p>I have created a sample application using Stackblitz with Angular and reactive forms - <a href="https://stackblitz.com/edit/github-hayn68-yjqorz" rel="nofollow noreferrer">https://stackblitz.com/edit/github-hayn68-yjqorz</a></p>