I am preparing for my CCENT exam and about 3-4 month ago, I had found a method of calculating subnet. Unfortunately I did not bookmark the site and i forgot how to do it.
All I remember is how you start.
You first build that table.
There is a 3rd column that you start from the middle after you are done with the first 2.
I dont remember where it starts.
If someone have seen this way of doing it and can explain it properly or link to the site that suggest this method.