• aberrate_junior_beatnik@midwest.social
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    18 days ago

    Common core made an effort to teach kids to think about numbers this way and people flipped the fuck out because that wasn’t how they were taught. Still mad about that.

    • kryptonianCodeMonkey@lemmy.world
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      18 days ago

      The problem with common core math was not that they taught these techniques. It’s that they taught exclusively these techniques. These techniques are born from the meta manipulation of the numbers which comes when you have an understanding of the logic of arithmetic and see the patterns and how they can be manipulated. You need to understand why you can you “borrow” 1 from the 7 or the 9 to the other number and get the same answer, for example. It makes arithmetic easier for those who do it, yes, but only because we understand why you are doing it that way.

      When you just teach the meta manipulation, the technique, without the reason, you are teaching a process that has no foundation. The smarter kids may learn to understand the foundational logic from that, but many will only memorize the rules they are taught without that understanding of why and then struggle to build more knowledge without that foundation later.

      Math is a subject where each successive lesson is built on the previous lessons. Without being solid on your understanding, it is a house of cards waiting to fall.

      • Rekorse@sh.itjust.works
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        18 days ago

        To add to this, people come up with math tricks all the time but you then have to check it against the manual method, and often multiple times with different numbers, before you can connect the manual process to the trick for later use.

        In my opinion I don’t think you can teach just the trick side of it, if thats what common core is.

  • Reddfugee42@lemmy.world
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    17 days ago

    You’re old school, like me. You’re literally describing the “new math” that boomers hate. Teachers are finally teaching kids to do it the way we’ve always done it in our head.

    “8 + 7 is awkward, but if you take two from seven and give it to eight, now you have 10 + 5 and that’s easy mental math.”

    • captainlezbian@lemmy.world
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      17 days ago

      And the reason they teach it that way is because it’s what the people who are good at math were already doing. Math isn’t about memorization it’s about understanding how numbers work and that’s how numbers work

  • peteypete420@sh.itjust.works
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    17 days ago

    No no no. Adding nine is just subtracting one, but adding to the front digit. 9 + 7 is actually 7 - 1=6, then add that 1 to the front. 16. Let’s not make more complicated than it needs to be.

  • technocrit@lemmy.dbzer0.com
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    18 days ago

    If your teacher gets mad about breaking an addition problem into easier problems, then that teacher should be fired. Phony tale.

  • blind3rdeye@lemm.ee
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    17 days ago

    Why are these posts always shitting on teachers? I don’t know what teachers you’re seeing, but I’ve never seen any teacher of any subject / age-group ever discourage anyone for thinking about something a different way. Quite the contrary, different ways of approaching problems are always encouraged.

  • smeg@feddit.uk
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    18 days ago

    Mental arithmetic is all little tricks and shortcuts. If the answer is right then there’s no wrong way to do it, and maths is one of the few places where answers are right or wrong with no damn maybes!