That is one of the fundamental problems in trying to think clearly about such distinctions; confusion of enumerative numbers and quantificative numbers. One tells you how many times to break open an egg; one tells you how much egg content to use. Usually we use enumeration as a convenient approximation, because it takes a big egg to be twice as big as a small egg, but if we had sparrows' eggs, hens' eggs, and ostrich eggs all mixed up, we might well stop speaking of "four eggs" and demand "100 grams of fresh egg content" or "henfruit juice" or the like. 

When we deal with tiny units such as grains of rice or quinoa, we stop enumerating and speak of "cupfuls" or kg or the like; similarly, when we speak of large items such as cattle, we speak of a "500 gm fillet for table 19", not "a cow for that guy who looks like he has already eaten one."