Flutter slider minimum

main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(
    MaterialApp(
      home: App(),
    ),
  );
}

class App extends StatefulWidget {
  const App({Key key}) : super(key: key);

  @override
  _AppState createState() => _AppState();
}

class _AppState extends State<App> {
  double value = 0;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: Center(
        child: Slider(
          value: value,
          min: 0,
          max: 20,
          divisions: 20,
          onChanged: (value) {
            if (value > 5) {
              setState(() {
                this.value = value;
              });
            }
          },
        ),
      ),
    );
  }
}