working with NSDecimalNumber and NSNumber

FROM : p.oleo@free.fr
DATE : Fri Jun 23 17:34:32 2006

Hi list

I was wondering what was the most efficient way to process 
calculations between an NSNumber and an NSDecimalNumber

should I use :

NSNumber *myNormalNumber;
NSDecimalNumber *myDecimalNumber;
[...]
myDecimalNumber =  [myDecimalNumber decimalNumberByMultiplyingBy:
[NSDecimalNumber decimalNumberWithString:[myNormalNumber stringValue]]];

or

myDecimalNumber =  [myDecimalNumber decimalNumberByMultiplyingBy:
[NSDecimalNumber decimalNumberWithDecimal:[myNormalNumber 
decimalValue]]];
(documentation says that decimalValue's value returned isn’t 
guaranteed to be exact for float and double values)

or should I use parent methods From NSNumber like numberWithFloat:  ?

I use NSDecimalNumber for money related values so my calculations 
need to be as precise as possible ...


Regards

Pierre Oleo