[aleph_minus_one]

> we don't use leagues or furlongs. I know what a chain is because i have one, but that's specifically to measure land against a plat map. Every location in this country is based off common reference locations (there's a literal marker on the ground)

The same holds for more obscure unit prefixes in the SI system like dam (decameter) or hm (hectometer) in the SI unit system (as far as I am aware, the only common usage of the "deca" prefix is in Austria for "decagram" (dag)).

Nevertheless, even these obscure units fit the regular pattern perfectly:

1 km = 10 hm = 100 dam = 1000 m

- and this was my point.

[genewitch]

I forgot one thing. you said "why not have in^2 and in^3" we do, but we don't use that very often. Older American "muscle cars" engines' displacement was measured in cubic inches. every child learns what a square inch is. a "board foot" is 12 cubic inches of milled wood, 12 in^3 - I don't know how to verify this on a Sunday, so this may be wrong, the board-foot. And then, we use square feet; for floor space in a house, say, my house is ~1500 ft^2. We also use cubic yards, yd^3, for stuff like dirt, concrete. when talking about this, like if i need a driveway's worth of concrete, the load is measured in "yards" which is short for "cubic yards."

But all that aside, and with apologies to mods and you for sneering; i wanted to say this in my prior reply but when reading it aloud to my wife i took it out:

Americans can, in general, divide and multiply by numbers other than 10.

yes, we use acres and hectares, too! it sounds better to say i live on 6.5 acres to an American neighbor who asks, than 0.02630457km^2...

[genewitch]

edit window closed but i wanted to say that i like that metric units are all related. 1cc of water is 1ml is 1g. that's lovely, and pretty, in the sense that Carl Sagan would use it.

Doesn't mean the USA has to switch for common use.