Flutter Dart Calculate Find Cube Or N Power Of Exponent

import 'package:flutter/material.dart';
import 'dart:math';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
  double Number1 = 9;
  double Number2;
  findSquareRoot() {
    Number2 = pow(Number1, 4);
    print(Number2);
  }
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
        home: Scaffold(
            body: Center(
                child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                      Container(
                          margin: const EdgeInsets.fromLTRB(20, 10, 20, 10),
                          child: RaisedButton(
                            onPressed: () => findSquareRoot(),
                            child: Text('Find Cube Of Given Number'),
                            textColor: Colors.white,
                            color: Colors.deepOrangeAccent,
                            padding: EdgeInsets.fromLTRB(12, 12, 12, 12),
                          )),
                    ]))));
  }
}