title: What class to use for money representation?
body: <p>What class should I use for representation of money to avoid most rounding errors?</p>
  
  <p>Should I use <code>Decimal</code>, or a simple built-in <code>number</code>?</p>
  
  <p>Is there any existing <code>Money</code> class with support for currency conversion that I could use?</p>
  
  <p>Any pitfalls that I should avoid?</p>