using System;

public class Program

{

    public static void Main()

    {

        long totalDocuments = 3;

        int pageSize = 2;

​

        var totalPagesWithLongAndInt = Convert.ToDecimal((totalDocuments / pageSize));

        var calcPagesWithLongAndInt = Math.Ceiling(totalPagesWithLongAndInt);

​

​

        Console.WriteLine($"TotalPages = {calcPagesWithLongAndInt} (totalPages was {totalPagesWithLongAndInt} before applying Ceiling)");

​

        var totalPagesWithDecimal = (Convert.ToDecimal(totalDocuments) / pageSize);

        var calcPages = Math.Ceiling(totalPagesWithDecimal);

​

        Console.WriteLine($"TotalPages = {calcPages} (totalPages was {totalPagesWithDecimal}  before applying Ceiling)");

    }

}

​