I'm trying to figure out of my 24 bit adder is simulating properly but I
can't seem to get my binary skills straight with carry and all that so I
don't really know if I'm doing it properly by hand.

Here's what I'm putting through the simulation:

Number 1:    00000000 11111111 11111111
Number 2:    01100100 11111111 11111111

The simulator gives out the 24 bit result:
                    01100110 00000010 11111101

I'm trying to decide if this is correct.  So I guess first, is it correct?
Then, how DOES it work by hand again?
I think I have the basics, 1+1=10, 1+0=1 0+0=0  etc....but....I can't make
it work in my head.