using System;

​

public class Program

{

    public static void Main()

    {

​

        decimal d = 1.000250m;

        var result = d.Round();

        Console.WriteLine($"Value: {d}, Result: {result}, Expected: 1.0003");

        Console.WriteLine();

        d = 1.000350m;

        var result2 = d.Round();

        Console.WriteLine($"Value: {d}, Result: {result2}, Expected: 1.0004");

    }

​

}

​

public static class  intHelper {

    public static decimal Round(this decimal d, int precision = 4){

        return Math.Round(d, precision);    

    }

}

​

​