This protocol defines the interface to objects that control aspects of the behavior of NSDecimalNumber objects. In particular, there are three methods that classes implement to specify rounding behavior, number precision, and a means for handling calculation errors. The Foundation framework implements this protocol in the class NSDecimalNumberHandler.

@protocol NSDecimalNumberBehaviors
// Instance Methods
- (NSRoundingMode)roundingMode;
- (short)scale;
- (NSDecimalNumber *)exceptionDuringOperation:(SEL)operation error:(NSCalculationError)error leftOperand:(NSDecimalNumber *)leftOperand rightOperand:(NSDecimalNumber *)rightOperand;
@end