Class Description
NSDecimalNumber, an immutable subclass of NSNumber, provides an object-oriented wrapper for doing base-10 arithmetic. An instance can represent any number that can be expressed as mantissa x 10^exponent where mantissa is a decimal integer up to 38 digits long, and exponent is an integer from -128 through 127.
Apple Documentation
http://developer.apple.com/documentation/Cocoa/Reference/Foundation/Classes/NSDecimalNumber_Class/
See Also
*NSDecimalNumberHandler
*NSDecimalNumberBehaviors
*NSNumber