title: I am not quite sure what is math.ceiling doing here
body: <p>Can somebody please tell me what is math.ceiling function doing here because I think Math.Pow will do the job without it? You don't need the rest of the code to understand because the code would do the same without Math.Ceiling. I just need information whether Math.Ceiling makes sure that Math.Pow has really calculated its number in the right way or does it mean something else. Thanks in advance</p>
  
  <pre><code>a[i] = a[i-1] * 10 + 45 * (int)(Math.Ceiling(Math.Pow(10, i-1)));
  </code></pre>