Learning Rounding and Truncation from the Maths library, C#

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//Title of this code
//Rextester.Program.Main is the entry point for your code. Don't change it.
//Compiler version 4.0.30319.17929 for Microsoft (R) .NET Framework 4.5

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
using System.Collections;

namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {
            // Learning to round / truncate a float number 
            
            float myFloat = 23.654586f;
            Console.WriteLine("original number: 23.654586\n");
            Console.WriteLine(string.Format("myFloat.ToString(): {0} (default setting is 5 dec places with rounding)\n",myFloat.ToString()));
            
            Console.WriteLine(string.Format("float.ToString(\"F4\"): {0} (has rounding)\n",myFloat.ToString("F4")));
            
            Console.WriteLine("converting a truncated string of a float, back to a float number");
            Console.WriteLine(string.Format("float.Parse(float.ToString): {0}\n",float.Parse( myFloat.ToString("F3") ))); // converted to string converted back to float
            
            Console.WriteLine("directly rounding off a float number. must include System.Collections class");            
            Console.WriteLine(string.Format("Math.Round(float,1): {0}",Math.Round( myFloat, 1 )));
            
            Console.WriteLine(Math.Truncate( myFloat));
        }
    }
}

Show compiler warnings [ + ] Show input
Compilation time: 0.11 sec, absolute running time: 0.08 sec, cpu time: 0.06 sec, average memory usage: 16 Mb, average nr of threads: 4