• BilboBargains@lemmy.worldEnglish
    4·
    12 hours ago

    Is this mostly a ADHD thing? They tried to make me learn times tables at school but that never stuck. Recently had to solve a problem with a CRC and part of that was manually calculating a long division in binary. At some point realised I didn’t even know how to do that in decimal so wound the clock back 35 years and learnt it from scratch. Badda bing badda boom, working CRC 🤓

  • alexcleac@szmer.infoEnglish
    1·
    14 hours ago

    I usually do that approach with multiplication of big numbers and square root calculation. Usually make it at most 10% error, which I consider quite a win :)

    • Sludgeyy@lemmy.worldEnglish
      1·
      4 hours ago

      This is part of common core math

      Making Tens (and Hundreds): Composing and decomposing: Students learn to break down numbers to make friendly numbers like 10 or 100, which are easier to add. Example: To add 8 + 5, they might see that 8 needs 2 to make 10. They could take 2 from the 5, leaving 3. Then, they add 8 + 2 = 10, and 10 + 3 = 13.

      They are teaching new students this

  • drperil@lemm.eeEnglish
    24·
    1 day ago

    Is this not just how people do simple math? Why the hell else did they make us just memorize multiplication tables?

    • froh42@lemmy.worldEnglish
      1·
      13 hours ago

      In elementary school my son would not memorize addition and multiplication and just use strategies like this.

      That became a problem later on as we just can handle a finite number of intermediary results in our brain, so just memorizing the tables reduces a lot of mental load for calculation in your brain.

      Another thing that helped him a lot was just writing down intermediaries on a piece of paper.

      Btw it was a bit similar for me, I just got the table memorized perfectly and got faster doing simple calculations in my mind than using a calculator when I was training the multiplication and addition tables with my son.

    • funkless_eck@sh.itjust.worksEnglish
      2·
      1 day ago

      three of the six falls into the gap between the 7 and 10, leaving 3 sticking out the top = 13.

      I have no idea if this is normal or not

  • Agent641@lemmy.worldEnglish
    11·
    1 day ago

    I would actually step to 10 first by going (7+3)+(6-3)

    Steal some from the 6 to make the 7 round up to 10, then ad the remainder to 10.

    • Owl@mander.xyzEnglish
      5·
      2 days ago

      Yeah, kinda annoying

      Btw this might break rule 1, sincerely idk

    • plyth@feddit.orgEnglish
      117·
      2 days ago

      Adding up to 10, like the other comment explains, is the common way. Using 14 as intermediate step suggests a different way of thinking. OP could be on to something if that’s normal to you.

      7 + 6 = 10 + 3 = 13

      • PotatoesFall@discuss.tchncs.deEnglish
        15·
        2 days ago

        Some people have 7+6 = 13 memorized.

        Some do 1+6+6 = 1+12 = 13.

        Some use offsets from 5, like 5+1+5+2 = 2*5 + 3 = 13

        Hell I’m sure somebody did it like 10 - 4 + 10 - 3 = 20 - 7 = 10 + 10 - 7 = 10 + 3 = 13

        • plyth@feddit.orgEnglish
          112·
          2 days ago

          Now determine the correlation between the various methods and adhd. My guess is that people with adhd are more likely to use the more exotic methods.

            • plyth@feddit.orgEnglish
              12·
              1 day ago

              I am wondering about the downvotes. You mean it is offensive to assume that something is different? Thank you for that feedback. I would have never guessed.

              • Feathercrown@lemmy.worldEnglish
                5·
                1 day ago

                I think people just aren’t on board with your guess, and don’t want to assign every behavior’s root cause to having ADHD

            • plyth@feddit.orgEnglish
              3·
              1 day ago

              Indeed. The important part are the experiments to determine the correlations. Without those every opinion about OP’s hypothesis in this post is as useless as my guess.

  • Thorry84@feddit.nlEnglish
    70·
    2 days ago

    I don’t think this has anything to do with ADHD, it’s just a little shortcut you can use when doing math in your head. I was taught techniques like this in school when we learnt addition and subtraction etc.

    • magic_lobster_party@fedia.io
      18·
      2 days ago

      It’s also a good way to double check your answers. If you can reach to the same conclusion through different processes, then it’s probably the right answer.

  • Archangel1313@lemmy.caEnglish
    18·
    2 days ago

    This is just what’s called the “common core method”. It’s now the preferred method of teaching math in many Western countries.

    • gandalf_der_12te@discuss.tchncs.deEnglish
      2·
      1 day ago

      idiology! they’re indoctrinating our children with this woke bullshit now. they’re trying to make us see the “common core” in things. What’s next, they’re gonna tell us that mexicans are people too?