Adding methods to Integers...

Background:
::::::::::::::::::::::

        The most recent MathFactor Podcast ( http://mathfactor.uark.edu/ )
        ended with a request to write a computer program that could, in
        principal, given enough time and memory, compute Graham's Number
        ( http://mathworld.wolfram.com/GrahamsNumber.html ).

        Smalltalk was a natural choice since it already supports LargeIntegers.

Problem:
:::::::::::::::

        Being new to Smalltalk, my first thought was that I should make my
        own class as a subclass of LargePositiveInteger, put my methods there,
        and violá.  Alas, no love.

        I ran into the following problems:
                * I couldn't find a way to give a value to myself.
                * I couldn't find a way to get integers to adapt to my class 
anyway.

        I ended up just adding my methods to the Integer class.  But, this felt
        very naughty.  Is it the usual approach?

Thanks,
Patrick



Bonus Questions:
:::::::::::::::::::::::::::::

	[ Actually, this section should be titled, "Bonus Questions: which  
it turns
	out that I managed to answer for myself, but have left here for  
pedagogic
        reasons". ]

        What I really want at the moment is to know if adding methods to the
	Kernel classes is considered legit.  But, I ran into a whole set of  
other
	questions along the way.  So, I wouldn't mind a little guidance on  
these
        either.

        The new: method:
        ::::::::::::::::::::::::::::::

        The withAtLeastNDigits method of LargePositiveInteger does this
        (variable names changed for clarity):

                nn := self class new: nDigits.

        I cannot find the "new:" method in the class browser under Class,
	nor can I find any hint of it somehow being part of  
LargePositiveInteger,
        Integer, Number, Magnitude, Object, or ProtoObject.  Actually, I just
        answered this one myself.... the Class class's hierarchy is
	Class < ClassDescription < Behavior < Object.  The "new:" is in  
Behavior.

        Initialization methods?:
        :::::::::::::::::::::::::::::::::::::::

        The only way that I can understand the "i" and "hours" methods of the
        Number class are if I somehow think the Complex and Duration classes
        have class methods in addition to their instance methods.  For example,
        here is the "i" method of the Number class.

                i
                        ^ Complex real: 0 imaginary: self

        That seems straightforward enough.  Given a number, say "5" and pass
	it the "i" message.  It will return a complex number with 0 for the  
real
        and 5 for the imaginary.  Except, I can't where the "real: imaginary:"
        method is defined with the class browser.

	Blah, and I just answered this one, too.  I hadn't twigged on the  
"class"
        button at the bottom of the class-list in the browser.  Now, I see.