• Shampiss@sh.itjust.works
    link
    fedilink
    English
    arrow-up
    25
    arrow-down
    2
    ·
    4 months ago

    Divide 1 by 3: 1÷3=0.3333…

    Multiply the result by 3 reverting the operation: 0.3333… x 3 = 0.9999… or just 1

    0.9999… = 1

    • ColeSloth@discuss.tchncs.de
      link
      fedilink
      English
      arrow-up
      1
      arrow-down
      10
      ·
      4 months ago

      You’re just rounding up an irrational number. You have a non terminating, non repeating number, that will go on forever, because it can never actually get up to its whole value.

      • WldFyre@lemm.ee
        link
        fedilink
        English
        arrow-up
        12
        arrow-down
        1
        ·
        4 months ago

        1/3 is a rational number, because it can be depicted by a ratio of two integers. You clearly don’t know what you’re talking about, you’re getting basic algebra level facts wrong. Maybe take a hint and read some real math instead of relying on your bad intuition.

        • ColeSloth@discuss.tchncs.de
          link
          fedilink
          English
          arrow-up
          1
          arrow-down
          12
          ·
          4 months ago

          1/3 is rational.

          .3333… is not. You can’t treat fractions the same as our base 10 number system. They don’t all have direct conversions. Hence, why you can have a perfect fraction of a third, but not a perfect 1/3 written out in base 10.

          • WldFyre@lemm.ee
            link
            fedilink
            English
            arrow-up
            14
            ·
            4 months ago

            0.333… exactly equals 1/3 in base 10. What you are saying is factually incorrect and literally nonsense. You learn this in high school level math classes. Link literally any source that supports your position.

          • pyre@lemmy.world
            link
            fedilink
            English
            arrow-up
            5
            ·
            4 months ago

            .333… is rational.

            at least we finally found your problem: you don’t know what rational and irrational mean. the clue is in the name.

            • Klear@sh.itjust.works
              link
              fedilink
              English
              arrow-up
              1
              ·
              4 months ago

              TBH the name is a bit misleading. Same for “real” numbers. And oh so much more so for “normal numbers”.

              • pyre@lemmy.world
                link
                fedilink
                English
                arrow-up
                3
                ·
                4 months ago

                not really. i get it because we use rational to mean logical, but that’s not what it means here. yeah, real and normal are stupid names but rational numbers are numbers that can be represented as a ratio of two numbers. i think it’s pretty good.

                • Klear@sh.itjust.works
                  link
                  fedilink
                  English
                  arrow-up
                  1
                  ·
                  4 months ago

                  I know all of that, but it’s still misleading. It’s not a dumb name by any means, but it still causes confusion often (as evidenced by many comments here)

                  • pyre@lemmy.world
                    link
                    fedilink
                    English
                    arrow-up
                    3
                    ·
                    4 months ago

                    fair enough, but i think the confusion for that commenter comes from a misunderstanding of the definition of the mathematical concept rather than the meaning of the English word. they just think irrational numbers are those that have infinite decimal digits, which is not the definition.

    • ArchAengelus@lemmy.dbzer0.com
      link
      fedilink
      English
      arrow-up
      6
      arrow-down
      26
      ·
      4 months ago

      In this context, yes, because of the cancellation on the fractions when you recover.

      1/3 x 3 = 1

      I would say without the context, there is an infinitesimal difference. The approximation solution above essentially ignores the problem which is more of a functional flaw in base 10 than a real number theory issue

      • Shampiss@sh.itjust.works
        link
        fedilink
        English
        arrow-up
        23
        arrow-down
        1
        ·
        edit-2
        4 months ago

        The context doesn’t make a difference

        In base 10 --> 1/3 is 0.333…

        In base 12 --> 1/3 is 0.4

        But they’re both the same number.

        Base 10 simply is not capable of displaying it in a concise format. We could say that this is a notation issue. No notation is perfect. Base 10 has some confusing implications

        • ColeSloth@discuss.tchncs.de
          link
          fedilink
          English
          arrow-up
          1
          arrow-down
          9
          ·
          4 months ago

          They’re different numbers. Base 10 isn’t perfect and can’t do everything just right, so you end up with irrational numbers that go on forever, sometimes.

      • chaonaut@lemmy.world
        link
        fedilink
        English
        arrow-up
        10
        arrow-down
        1
        ·
        4 months ago

        This seems to be conflating 0.333...3 with 0.333... One is infinitesimally close to 1/3, the other is a decimal representation of 1/3. Indeed, if 1-0.999... resulted in anything other than 0, that would necessarily be a number with more significant digits than 0.999... which would mean that the ... failed to be an infinite repetition.