On Tue, 10 Jul 2001, Michael Neumann wrote:

> Because Fixnum's do not really exist in memory, you cannot change their value.
> But look at Perl, Python or Smalltalk, they work the same way, or is there for every
> number an object in memory?
> 
> Numbers are first class objects. But they are passed by value not by reference.

That's probably the most useful way of looking at it, but I just think of
Numbers as being normal objects that happen not to have *any* mutating
methods, or accessible state... the semantics work out the same either
way, as far as I can tell.