Tabuada_operacoes

// Bibliotecas
import 'dart:io';

// Funcao principal
main() {
  int i = 1;

  while (true) {
    int resp = menu();
    if (resp == 0) {
      break;
    } else if (resp > 0 && resp < 5) {
      // Entrada de dados
      stdout.write("\n# Tabuada de qual numero: ");
      double n = double.parse(stdin.readLineSync()!);
      print("=====================================");

      // Estrutura de repeticao
      while (i < 11) {
        if (resp == 1) {
          print("# $n + $i = " + (n + i).toStringAsFixed(2));
        } else if (resp == 2) {
          print("# $n - $i = " + (n - i).toStringAsFixed(2));
        } else if (resp == 3) {
          print("# $n / $i = " + (n / i).toStringAsFixed(2));
        } else if (resp == 4) {
          print("# $n * $i = " + (n * i).toStringAsFixed(2));
        }

        // Incremento
        i++;
      }
      print("=====================================");
      i = 1;
    }
  }
}

int menu() {
  print("\n===== Menu =====");
  print("[1] Adicao ");
  print("[2] Subtracao");
  print("[3] Divisao");
  print("[4] Multiplicacao");
  print("[0] Exit");

  stdout.write("# Opc: ");
  return int.parse(stdin.readLineSync()!);
}