Comment on A fake Facebook event disguised as a math problem has been one of its top posts for 6 months

• SmartmanApps@programming.dev ⁨4⁩ ⁨days⁩ ago

  I fully agree that if it comes down to “left to right”

  It never does

  But I’ve just shown why that “rule” is a common part

  No you didn’t. You showed you didn’t understand the rules. Doing addition first for 10-1+1 is 10+1-1, not 10-(1+1). It literally means add all positive numbers together first, which are +10 and +1, as per Maths textbooks…

  Image

  Note in the above simplification of the coefficients we have 6-11+5-7+2=6+5+2-11-7=13-18=-5, and not, as you claim 6-(11+5)-(7+2)=6-16-9=-19

  because it is so weird and quite esoteric

  It’s a convention, not a rule, and as such can be completely ignored by those who understand the rules. See literal textbook example

  source

  • HereIAm@lemmy.world ⁨4⁩ ⁨days⁩ ago

    I know it’s not a rule, hence why I put it in quotation marks. I noted in another comment that, yes, the proper way is to group it as 1+(-2)+3 and you can do it in any order. What I meant with ““rule”” is the meme questions pray on people not understanding/remembering what the actual rules are or why “left to right” conventions exist.

    source

    • SmartmanApps@programming.dev ⁨3⁩ ⁨days⁩ ago

      the proper way is to group it as 1+(-2)+3

      No it isn’t.

      you can do it in any order

      You can do it in any order anyway

      left to right 1-2+3=-1+3=2

      addition first 1+3-2=4-2=2

      subtraction first -2+1+3=-1+3=2

      right to left 3-2+1=1+1=2

      What I meant with ““rule”” is the meme questions pray on people not understanding/remembering what the actual rules are

      And you showed that you were one of them. Every answer you got other than 4 was wrong, because you didn’t understand the rules. spoiler alert: doing it in different orders never means add brackets to it. Addition first for 10-1+1 is 10+1-1, not 10-(1+1). See previous textbook example

      source