There are two ways to do fat in the Zone. The Zone numbers are calculated so that one (truly whole) block of fat is 3 grams, or 27 total calories, 30% of fat intake.
One is the "ASSume" method, where you assume that every block of "lowfat" protein contains 1.5 grams of fat, and thus make the actual counting of fat blocks at 1.5 grams of fat per block.
The other method is the anal/OCD method, where you count all fat from all sources and tally your blocks up as 3 grams of fat per block from all sources.
I prefer the second method, and I don't Zone anymore. The second method becomes much easier when doing the "Athlete's Zone", where the fat intake is ramped up in multiples.