How do a calcul with int come to provider in flutter

I'm beginner in flutter and provider. I managed to retrieve a value from a widget to the parent widget with provider. This value is an int.

Text( context.watch<EweProvider>().configSouteProvider,
              style: const TextStyle(
                fontWeight: FontWeight.bold,
                fontSize: 25,
              ),

I would like to be able to do calculations with the int that I retrieve this way.

How to do it? Is that possible to do that directly with flutter without provider ?

THANKS

This is a part of my code

/// création de la classe a ecouter
class EweProvider extends ChangeNotifier {
  var configSouteProvider;
  var eweValueProvider;
  EweProvider({
    this.configSouteProvider = "0",
    this.eweValueProvider = "0",
  });

  void changeconfigSouteProvider({required
    String newConfigSoute,
  }) async {
    configSouteProvider = newConfigSoute;
    notifyListeners();
  }
  void changeEweValueProvider({required
  int newEweValue,
  }) async {
    eweValueProvider = newEweValue;
    notifyListeners();
  }


}

            RadioMenuButton(
              child: Text('14 sièges'),
              value: '14 sièges',
              groupValue: selectedConfigSoute,
              onChanged: (selectValue){
                setState(() {
                  selectedConfigSoute = selectValue!;
                  configSoute = 120;
                  context.read<EweProvider>().changeconfigSouteProvider(newConfigSoute: configSoute.toString());
                  calculEwe();
                });
              },
            ),