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Joined 7 months ago
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Cake day: April 11th, 2024

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  • I get that. I like the number line approach, and respect it, but I have also observed seasoned math coaches fumble the visual explanation of a division by fractions problem where the numerators and denominations were relatively prime. As soon as the guy had drawn the first fraction and began to say, “we’d multiply by the recipro-…”, I could tell it was going to be long problem. He just stood there, and then asked, “well, how would I go about explaining the ‘keep change flip’, if you will?” He ended the problem by saying he might just explain that the distance drawn for the first fraction needs to be repeated on the other side of the fraction to show the multiplication by the denominator of the second fraction, and then that distance could be broken into parts to demonstrate the division by the previous numerator of the second fraction.

    Basically he ended the problem by saying, “let’s just reflect it! Then we can break it up.” There wasn’t really a sound justification for the reflection piece of the process, other than saying, “we need to multiply by the reciprocal of the second fraction, so we’ll just have to multiply by its denominator it had, prior to flipping it.”

    That was the quietest meeting I have ever seen amongst that group of adults.


  • ParabolicMotion@lemmy.worldtoMemes@lemmy.mlmath is hard
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    6 months ago

    It’s going to be okay:

    Edited to add this: Singapore math insists however, that we eliminate the use of visuals in describing arithmetic within the rationals. They encourage that users of common core rely upon the number line, and solely the number line for thorough and most mathematically sound representations of arithmetic, even when involving the division of fractions.

    For those not up to speed to with common core, remember how the teacher used to draw a diagram of a bunny hopping from one integer to the next integer to represent adding given integers, such as 4+3, or -2+1? Imagine that representation being used with problems like 1/7 divided by 5/49, and no decimal approximation is allowed. It’s fascinating and truly something to appreciate from the standpoint of someone who truly loves mathematics. I think it makes for great discussions amongst math graduates like myself, and other math enthusiasts. What does that mean for those who are not so enthused? Sometimes it means the teacher receives death threats from angry students. You can’t make everyone happy.







  • This. I experienced Redditors calling me “Nazi”, after I posted a pic to Reddit’s “bald”. They failed to realize that Hitler never shaved his head; he shaved the heads of his prisoners. I tried explaining this to people, and reassured them that my grandparents served on the side of the Allies, during WW2. I still have people who have stalked my profile all the way to Lemmy, perhaps even doxing me, to continue their harassment. I’m not even German, or male, and I get bombarded with commenters accusing me of being a male “Nazi”. Not even “neo-Nazi”. They keep specifically referencing Germany and WW2, and like I said, I’m not even German by dna.