A simple calculator build in Flutter.


  • lib/services/calculator.dart evaluates expressions using the package math_expressions.
  • lib/widgets/calculator_button is a simple widget which acts as a calculator button (for operands and operators).
  • lib/widget/home_screen is a StatefulWidget which deals with button presses and updating output display.
  • On iOS, the launch screen is the same color as scaffoldBackgroundColor.


  • On each button press, the HomeScreen’s whole widget tree is rebuilt.
  • The Align widget is really useful and isn’t something I’ve stumbled across before.



This post was generated from a GitHub repository.