• argh_another_username@lemmy.ca
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    2 days ago

    This is even more interesting if you notice that Americans use fractions a lot, maybe even more than countries with metric system. It’s 1/2 pound, 5/8 inch, 3/4 mile and so on. Countries with metric system just change the units. Typically we don’t say 1/2 km, we say 500m.

    • Rivalarrival@lemmy.today
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      2 days ago

      We use power-of-two denominators. 1/2, 1/4, 1/8, 1/16, 1/32. We don’t use 1/3, 1/6, 1/9, 1/12, 1/5, 1/7.

      We intrinsically know that 1/2 and 16/32 are equivalent; we would have to think about 3/6 or 6/12.

    • ricecake@sh.itjust.works
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      2 days ago

      That’s interesting. I never really noticed it but I’m not a fan of changing units. Whatever the “base unit” is for something is what I’ll use, even if it crosses the order of magnitude threshold.
      Metric always gets decimal though, and sae units get fractions.

      I’ve gotten myself switched to metric for kitchen weights and volume, and for small distances in projects I’m working on.
      I’ll buy a 1/2 pound of meat, and then measure out 200 grams, with 100 ml of stock and 0.5 grams of something-small-i-cant-think-of-for-an-example-recipie.
      Saying 500 milligrams feels wrong. So does asking for 1000 ml of pop though, since that’s the “wrong unit”.

      I think there’s something baked into the American brain that says unit conversion is a source of error and should be avoided. Converting from 1 mile to 2640 feet is obviously gonna cause issues.

      As for the fractions, I think that’s because sae units developed in a context where division by whole numbers was helpful, and metric was designed so that division by 10 was consistent and predictable.
      Nothing intrinsically wrong with fractional units, other than 1/3 meter being a less reasonable number of centimeters than the inches in 1/3 yard.

      • Obi@sopuli.xyz
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        2 days ago

        There’s no change of “unit” when going from km to m or ml to L, etc. It’s just the next “size” up or down, we immediately know 500m is half a km.

        • ricecake@sh.itjust.works
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          1 day ago

          I know it’s not actually a unit change, but in my head there’s a resistance to changing the scale.

          If one sign says 5km, I expect the next sign to say 0.5km, not 500m.

    • davidgro@lemmy.world
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      2 days ago

      I suppose it’s much more rare for us to use 1/3 specifically. It does show up in cooking, but even there it’s hidden in the units a lot of the time.