Sorry but that url doesn't help me. I get nothing although I do get a tiny pic page.
I don't use this "formula" method because it takes me longer to classify group #, bonds, and lone pairs than to count. Here is how you can count them.
Count electrons around an atom as follows:
1 each for unshared electrons. Electrons shared between atoms--give half of the electrons in the bond to each atom. The formal charge is then What it should have - what it has. For H2O,
So H has 1 electon, it should have 1, FC = 0
Other H is the same.
O. We have 2 electrons at the top and two on the right side (total now 4) + 1 electron for 1 H -O bond and 1 for the other H-O bond which makes 6. It should have 6. FC = 0