• I Cast Fist
    link
    fedilink
    English
    257 months ago

    The problem is that there’s no “external” parentheses to really tell us which is right: (8 / 2) * 4 or 8 / (2 * 4)

    The amount of comments here shows how much debate this “simple” thing generates

    • @qarbone@lemmy.world
      link
      fedilink
      English
      327 months ago

      When there are no parentheses, you process left to right on the same tier of operations. That’s how it’s always been processed.

    • @EvokerKing@lemmy.world
      link
      fedilink
      207 months ago

      Afaik the order of operations doesn’t have distributive property in it. It would instead simply become multiplication and would go left to right and would therefore be 16.

    • @Aermis@lemmy.world
      cake
      link
      fedilink
      117 months ago

      If you agree that parenthesis go first then the equation becomes 8/2x4. Then it’s simply left to right because multiplication does not take precedence over division. What’s the nuanced talk? That M comes before D in PEMDAS?

      • I Cast Fist
        link
        fedilink
        English
        27 months ago

        My observation was mainly based on this other comment

        https://programming.dev/comment/5414285

        In this more sophisticated convention, which is often used in algebra, implicit multiplication is given higher priority than explicit multiplication or explicit division, in which those operations are written explicitly with symbols like x * / or ÷. Under this more sophisticated convention, the implicit multiplication in 2(2 + 2) is given higher priority than the explicit division in 8÷2(2 + 2). In other words, 2(2+2) should be evaluated first. Doing so yields 8÷2(2 + 2) = 8÷8 = 1. By the same rule, many commenters argued that the expression 8 ÷ 2(4) was not synonymous with 8÷2x4, because the parentheses demanded immediate resolution, thus giving 8÷8 = 1 again.

      • If you agree that parenthesis go first then the equation becomes 8/2x4

        No, it becomes 8/(2x4). You can’t remove brackets unless there’s only 1 term left inside. Removing them prematurely flips the 4 from being in the denominator to being in the numerator, hence the wrong answer.