• glibg@lemmy.ca
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      4 hours ago

      My thought exactly. I resonate with this meme but I also try to challenge myself to do math longhand on paper

  • RBWells@lemmy.world
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    15 hours ago

    I am an accountant, literally work all day with numbers. 8+7, fine, that’s 16 minus one or 14 plus one.

    8x7? Never managed to memorize the times tables so that is, well 4 7s is 14 +14, that’s 28, so 8 7s is 28 + 28, which is 40 and 16 so that’s 56.

    • MeThisGuy@feddit.nl
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      6 hours ago

      interesting how mathes works differently for many people. because I do 8+2 to get 10. then 7-2=5, so 10+5 = 15.

      • ThunderQueen@lemmy.world
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        3 hours ago

        Neat. I just remember that 8 is 2 less than 10 and 7 is 3 less than ten, so you can either do 8-3+10 or 7-2+10. Both are 15. Its similar to how you do it but for some reason its easier for me this way.

  • stinerman@midwest.social
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    19 hours ago

    In high school calc, I would do all kinds of algebra, integration, etc. and then at the end add 8 and 7 and get 13. All the time.

  • skisnow@lemmy.ca
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    20 hours ago

    I don’t know what to make of this comments section. This many people really don’t have 8+7 down?

    I don’t even feel superior about it, just bewildered.

    • Test_Tickles@lemmy.world
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      6 hours ago

      For us older folk, and unfortunately, also for some younger folk that grew up in more “conservative” small towns, borrowing and fancy math trickery was the work of the devil.
      We were required to memorize the addition tables as well as the multiplication tables. And even then, addition could be done on your fingers and toes so as long as you could add the big numbers like 8 & 7 together faster than the really slow kid could take off his shoes and work it the hard way, you were considered proficient at addition.
      So ya, there’s a wide swath of America that just sucks at basic math.

      • skisnow@lemmy.ca
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        18 hours ago

        Maybe I just have it fresher in my head because I play a lot of Killer Sudoku. 15 pair box? That’s a 7-8 or a 6-9.

    • BombOmOm@lemmy.world
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      19 hours ago

      In my case, the mental math trick suggestion (make it 10 + 5) was intended as a way to build a skill using the provided, easy example. That type of mental math can be applied to much larger numbers, particularly when combined with other mental math tricks.

  • notabot@piefed.social
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    21 hours ago

    This is why learning binary is so important. In base two, the same equasion is 1000+0111=1111, now you just convert back to decimal with: 8+4+2+1= sweats and starts counting on fingers before reaching for calculator

      • notabot@piefed.social
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        13 hours ago

        Right, as we all know, the most sensible way to do nonary algebra is in ternary, so we simply calculate 22+21 and convert back to nonary, and optionally decimal afterwards. So, 2 add 1 is 0, carry the 1, add it to 2 for 10, add the 2, carry the one, pad to 4 places and we have 0120, or 16 in base 9. Now to convert to decimal… removes shoes and socks

  • BombOmOm@lemmy.world
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    21 hours ago

    Mental math tricks are important.

    Take 2 from the 7 and give it to the 8. You now have 10 + 5. Much easier math.

    • Shelena@feddit.nl
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      19 hours ago

      Yes, that seems easier to me as well! I was not allowed to do this according to the teacher when I was a child. They wanted me to do it in some weird counterintuitive way. But I was very stubborn and I am still doing calculations in this way. She is not the boss of the way I think!

  • bacon_pdp@lemmy.world
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    21 hours ago

    8+7 = 8 + ( 2 + 5) = ( 8 + 2 ) + 5 = 10 + 5

    Then just do the column addition (1 + 0) =1 and (0+5)=5

    Thus concat(1,5) = 15

  • Thorry@feddit.org
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    19 hours ago

    When I’m doing woodworking and I need to add up some very simple measurements I always use a calculator. I could very easily do it in my head and often automatically do without even thinking about it. However I’ve learned the hard way it’s very easy to make a simple error with even something as simple as 8+7 and chances are you won’t find out till later when two parts don’t fit together. That’s 20 hours down the toilet, just because I didn’t double check using the shop calculator.

    • RedGreenBlue@lemmy.zip
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      17 hours ago

      I’m alright when it comes to mathematics, but my memory is a swiss cheese. I’ll do a calculation, context switch and 3 seconds later it’s either gone or I remember incorrectly. Having things written down, on paper or in a calculator, gives peace of mind.

    • RememberTheApollo_@lemmy.world
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      18 hours ago

      Totally this. Find an online calc that accepts fractions and just get it done right in a few seconds vs trying to convert to 16ths or some crap. Which is why I use all metric unless I’m forced into imperial units.

  • someguy3@lemmy.world
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    20 hours ago

    I once typed in 1+1, though it was several term equation and I was mentally reducing each term before punching it in.

  • gaiussabinus@lemmy.world
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    20 hours ago

    I am chronicly paranoid because I have had a low battery on an exam. I just type in simple math because it might be totally borked and you won’t catch it on something complex

      • AbsolutelyClawless@piefed.social
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        15 hours ago

        I can’t speak for low battery, but I can for different brands of calcs.

        Back in high school majority of students had this specific model, and I had a different one. My entire answer to a question on an exam was correct, but my calculator somehow calculated different decimals to the ones from the popular model. And it was like 4th, 5th decimal or something. The asshole teacher took all of my points away on that. Meanwhile, one of her fave students forgot a very important part of the formula which made the calculation completely wrong and the teacher still gave them half the points for it. God, I hated school, lol.

      • BombOmOm@lemmy.world
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        19 hours ago

        It…shouldn’t. The 7-segment displays will have contrast issues, then the whole thing will stop working entirely when the battery gets too low.

    • Eq0@literature.cafe
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      19 hours ago

      Same. In contexts where there are a lot of already taxing elements, there is just no mental bandwidth for switching gears and doing the calculations. So calculator it is. I do find it important to hone my skills from time to time, just not to lose them.