thank you for letting me work on this .

1. fixed the issue for SDK version. App can run on the latest android device now.
2. changes some little design aspects
3. Added functionality to change the app's color dynamically

There is no concrete way to handle negative numbers within this implementation.

For instance, if I want to calculate:

-85 + 6 or 76+(-87)

Then there is no way to handle that using the current implementation.

I just tried the calculator, and the approximations displayed here are't useful for most mathematics.

For instance, 1500/1536 equates to around 0.976 in reality. Rounded off, this could be displayed as 0.98.

But in here, it is being displayed as 1.0. Which is misleading.

All widgets get pushed up upon start because the keyboard launches. Add resizeToAvoidBottomPadding: false, to the Scaffold to prevent this. Though the better solution is to prevent the keyboard from popping up because it has to be manually dismissed before you can use the app. This was seen on iPhone only. I cannot verify the issue on Android.