using System;

class Program

{

    private static void Main(string[] args)

    {

        var num = "0.07";

        Console.WriteLine(IsNumber(num) ? 

            $"'{num}' is a number" : 

            $"'{num}' is not a number");

    }

    private static bool IsNumber(string num) => 

        decimal.TryParse(num, out _);

}