• untorquer@quokk.au
      link
      fedilink
      English
      arrow-up
      21
      ·
      5 days ago

      9/5(conversion ratio) of -40 is -72 which is 32(offset) below -40.

      So… (9/5[F/C])*(-40[C])+32=-40[F] is where they meet.

      • Stupidmanager@lemmy.world
        link
        fedilink
        English
        arrow-up
        3
        arrow-down
        2
        ·
        5 days ago

        I prefer the converted fractions for ease. Your solution while right will confuse most Americans. (1.8x-40c)+32=-40f

        Dear fellow Americans: Fun tip, lazy (but inaccurate) math is (2x-40c)+30= -50f which when you get to normal ranges works well enough in a margin of error. Or just learn to enjoy the beautiful thing that is Celsius and stop using/converting to Fahrenheit.

        • untorquer@quokk.au
          link
          fedilink
          English
          arrow-up
          2
          arrow-down
          1
          ·
          5 days ago

          Americans use fractions daily. The rest of the avoids them. The dimensional analysis maybe.

          I’ve done 9/5+32 in my head so much it’s easier and faster for me. Then it’s 100% accurate to boot.

          • Stupidmanager@lemmy.world
            link
            fedilink
            English
            arrow-up
            1
            ·
            4 days ago

            Normal should be subjective normal, -40 is an extreme temp and over 40c is also extreme. I’m talking 5-25c where the lazy math works well enough.

            So 20c is 68f proper conversion or 70f with lazy. 30, is 86f proper and 90f lazy. Basically for a normal day the temp is close enough that no one would notice.