Sum 1 With 1 Divided By N With Precision of 0.001

using System;
class Sum1With1DividedByNWithPrecision
{
  static void Main()
  {
    //Write a program to calculate the sum (with accuracy of 0.001): 1 + 1/2 - 1/3 + 1/4 - 1/5 + ...
    Console.Write("Please enter the end number of the interval:");
    int numberOfelements = int.Parse(Console.ReadLine());
    decimal sum = 1m;
    int i = 0;
    for (i = 2; i <= numberOfelements; i += 2)
    {
      sum += (1 / (decimal)i) - (1 / (decimal)(i + 1));
    }
    Console.WriteLine("The sum is: {0:.000}", sum);
  }
}