I found this link http://fengnet.com/book/CCNA%20Portable/ch02lev1sec2.html#ch02fig01
to explain how VLSM works, it shows step by step to find out each subnet with using VLSM. This is a good site so far amongs all others site which explain how VLSM works but I still got lost in Step 2.
In Step 2, the ".64" is picked for Network "A", why it is not ".0"?
The website author used .128/26 to break it into two for network "B", can he use .192/26 to break it instead of .128/26? If not, why?