title: How to use BigInteger in VS 2010
body: <p>I have been trying to use the BigInteger type, that is supposedly new in .NET Framework 4.0.</p>
  
  <p>I don't seem to be able to get to it, and get an error when trying to reference it via Using System.Numerics.</p>
  
  <p>Any idea what I'm doing wrong? Sorry if this is a stupid question...</p>