Here is a down-to-earth example of another unfamiliar set measurement parameters. Eggs are sold by the dozen, but they are actually priced by the pound. Farmers or egg sorting machines separate eggs into sizes we call small, medium, large, extra large and jumbo.
On the farm where I grew up we packed eggs into layers of 36, in an egg crate which held two stacks of 5 layers or 30 dozens. note A dozen large eggs weighs 24 oz or 1.5 lb. So the case weight is approximately 45 lbs. The vast majority of egg consumers wouldn't have a notion of what you were talking about if you were to say that eggs had just gone up by $1.50 per crate or $0.033 per pound, when the price per dozen had increased from $1.20 to $1.25. Of course they also would have no reason to care! For more on eggs check here, or try the British Egg Information Service. Note that the British have only recently adopted the same egg size standard as we use in the U.S.
[continued with other weird units of measure]