title: Get exponent of NSDecimalNumber in Objective-C?
body: <p>Given an NSDecimalNumber, how can I find the exponent (scale)?</p>
  
  <p>Although it should in principle be possible to do this by first converting to an NSString followed by some ugly string manipulation, I'd rather avoid it.</p>
  
  <p>With a Java BigDecimal, I can call the <a href="http://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigDecimal.html#scale%28%29" rel="noreferrer">scale()</a> method to get the scale.</p>
  
  <p>Does a similarly concise method exist for NSDecimalNumber?</p>