I’ve learned about them in school, but I’ve never heard anyone say something is 8 decameters long or anything like that. I’m an American.

  • OptimusPhillip@lemmy.world
    link
    fedilink
    arrow-up
    11
    ·
    1 year ago

    As an American who has gotten very used to metric units in studying engineering, the general rule I picked up is that you typically only change units every three orders of magnitude. So 8 decameters would typically be expressed as 80 meters, maybe 0.08 kilometers. Decameters and hectometers are a thing, but they’re not common units. Even centimeters don’t see much use compared to millimeters.

    • Siegfried@lemmy.world
      link
      fedilink
      arrow-up
      2
      ·
      1 year ago

      We usually go for the 3 order rule, but in the case of areas and volumes, for dimensional reasons, dam and hm make it into the three order rule. Dm (or dam) is not common but dam^3 has some uses, the same goes for hm, hm is used for only special situations (like meassuring train distances), but hm^2 is almost globally used for big chunks of land. Also, with hm^2, we always keep the unit, so for example, Parque Nacional Iguazú in Argentina has 67620 hm^2 (also ha or hectarea).

      I’m also an engineer and I generally despise imperial units, but I have to say that inchs are pretty handy and the 1 in = 25,4000… mm relation is pretty neat

    • Cralder@feddit.nu
      link
      fedilink
      arrow-up
      1
      arrow-down
      6
      ·
      edit-2
      1 year ago

      That might be true for science but in everyday use centimeters, hektograms and the like are more common