title: .NET method to round a number up to the nearest multiple of another number?
body: <p>I'm looking for a method that can round a number <em>up</em> to the nearest multiple of another.  This is similar Quantization.</p>
  
  <p>Eg.  If I want to round 81 up to the nearest multiple of 20, it should return 100.</p>
  
  <p>Is there a method built-in method in the .NET framework I can use for this?</p>
  
  <p>The reason I'm asking for a built-in method is because there's a good chance it's been optimized already.</p>