[lmm]

Compare equivalent accuracy. "one hundred and eighty three centimetres" is not noticeably more complex than "five feet seven and a half inches". And you have the option of "eighteen decimeters" if that's the level of accuracy you want - try inventing an intermediate unit on the fly with imperial.

[brc]

But you wouldn't go down to a half-inch, and there is a shortcut - '5 foot 7'. I'm not referring to accurate measurements, but the sort of day-to-day, rounded off measurements that pepper our daily speech.

If I said a decimeter to any of my friends, they would have no idea what I was talking about.

[lmm]

> there is a shortcut - '5 foot 7'

You can say "1 meter 83", and people do.

> If I said a decimeter to any of my friends, they would have no idea what I was talking about.

Well, mine would - and any who didn't could easily figure it out. If you're willing to memorize all the random names the imperial units have, you can afford to remember "deci".