Back on the subject of discussion (which is supposed to be dry vs. liquid yeast) according to http://www.mrmalty.com/pitching.php you need 180 billion cells for 5.25 gallons of 1.048 wort.
According to the same link (I couldn't find a reference on Wyeast's or White Labs' sites) the most a tube of liquid yeast has is 120 billion cells, 66% of what you'd need for that wort.
According to http://www.danstaryeast.com/tds/nottingham.pdf dry Nottingham yeast has 5 billion cells per gram, and it comes in 11 gram packets, which works out to 55 billion cells (30% of our pitching rate). To achieve 180 billions cells you'd need a bit more than 3 packets of Nottingham.
I see what you're saying, but, note, that Mr. Malty states that, for the parameters listed above you need to pitch 0.9 11.5gm packets of dry yeast for the same wort.