• edgemaster72@lemmy.world
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    4 months ago

    0.5 / 0.5 = 1, so reducing the top term by half (from 0.5 to 0.25) reduces the result by the same (from 1 to 0.5), makes perfect sense to me. Or, ya know, just remember that dividing by 0.5 is the same as multiplying by 2.

      • edgemaster72@lemmy.world
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        4 months ago

        I was trying to think how to put that into words with an example like, “how many halves fit in 10? It’s 20. So how many halves fit in a quarter? Only half of a half will fit, so 0.5” but I kept screwing up the wording in my head for halves and quarters until I read your reply, so thank you for helping with that clarification. I knew the math was right but couldn’t put it into words the way I wanted.

      • MeetInPotatoes@lemmy.ml
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        4 months ago

        Incorrect. The argument makes perfect sense, you just gave a reason for why the example’s initial point seems obvious. Proofs don’t need to be fancy or make novel arguments to be effective. It’s math, where the shortest distance between two points is a straight line.

      • qarbone@lemmy.world
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        4 months ago

        Is this a real stance you’re taking or are you just trolling? Explain yourself.

      • edgemaster72@lemmy.world
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        4 months ago

        If you have 0.5 / 0.5, that equals 1, because it’s a number (except 0), divided by itself. That much we seem to agree on.

        So then if we want to get from this to 0.25 / 0.5 as shown in the meme, we have to look at what’s changed and apply that change to each side of the equation. So what changed? The top of the fraction is 0.25 instead of 0.5. Hopefully we can agree that 0.25 is half of 0.5. We halved the top side of the fraction on the left.

        Now we want to apply that change on the right side then to keep our equation balanced. For this step, it helps to rewrite 1 on the right side as 1 / 1. Then we halve the top side of that fraction just like we did with the left side, giving us 0.5 / 1, which simplifies to just 0.5.

  • afraid_of_zombies@lemmy.world
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    4 months ago

    If you move it around it makes more sense.

    .25 = 0.5*0.5

    If you take half of something only half of the time you take a quarter of something.

  • SkyNTP@lemmy.ml
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    4 months ago

    Dividing by a division of 2… Of course it’s going to cancel out. Like subtracting a negative.

    Surely you don’t not understand double negatives? Just think of it like that.

  • Leviathan@lemmy.world
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    4 months ago

    Maybe someone better at math can answer this, but is 0.25/0.5 functionally the same as 0.5/1, or simply 0.5?

    • doctordevice@lemm.ee
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      4 months ago

      You can call it whatever you want, as long as it equals 1/2 it’s the same number.

      So yes, multiplying by 2/2 to make it more intuitively obvious is perfectly valid and a good way to think about it. Most arithmetic tricks are ultimately multiplying by 1 or adding 0 just to make the problem easier to handle.

      • Leviathan@lemmy.world
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        4 months ago

        Oh yeah, I just meant that they said I multiplied by 2, which in my head is 2/1 but I was multiplying by 1. Just trying to be clear.

    • 𝕾𝖕𝖎𝖈𝖞 𝕿𝖚𝖓𝖆@lemmy.world
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      4 months ago

      I think it’s easier to picture it in terms of fractions. When you divide by a fraction, you reciprocate the divisor. That is, you flip its numerator and denominator, then multiply them. In this case, we’re taking 1/4 and dividing it by 1/2. You take the reciprocal of 1/2, which is 2/1. Then multiply the numerators and denominators. You end up with (1/4)*(2/1)=2/4=1/2=0.5

    • Fellstone@lemmy.blahaj.zone
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      4 months ago

      0.25 is half of 0.5. Alternatively: A quarter is half of half. If you multiplied 0.25/0.5 by 2, then it would be 0.5/1, which is just 0.5.

        • Aleric@lemmy.world
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          4 months ago

          You’ve got it. The trick to working with fractions is multiplying them by fractional equivalents to one (2/2, 7/7, 13/13, etc) to change them into numbers that our monkey brains can handle more easily.

    • AnarchistArtificer@slrpnk.net
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      4 months ago

      Huh, that’s a cool way to think of it. I’ve done a decent amount of higher level maths but stuff like this always cooks my brain if I let it. I thought of the numbers as the fractions 1/4 and 1/2, which then reminds me that 1/2 * 1/2 = 1/4, but I think your way feels more elegant

    • intensely_human@lemm.ee
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      4 months ago

      I cannot comprehend how bad at math you need to be to ask this question.

      Like, 2 + 2 = 4 = 3 + 1.

      These are all equivalent. That’s what this symbol means: =

      • crapwittyname@lemm.ee
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        4 months ago

        There are better ways of saying this. You know, polite ways, where you don’t come across as an insecure dickhead.

      • SoleInvictus@lemmy.world
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        4 months ago

        I cannot comprehend the level of douchery required to mock someone for asking an honest question. It’s gotta be high, at least Summer’s Eve or beyond.

        The best part is how your answer is bad. It’s a correct statement but it doesn’t answer their question.

      • recapitated@lemmy.world
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        4 months ago

        That is really mean. You shouldn’t attempt to teach people anything if this is what your mindset is like.

  • recapitated@lemmy.world
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    4 months ago
    • 250 marbles / 500 kids = 0.5 marble per kid
    • 25 marbles / 50 kids = 0.5 marble per kid
    • 2.5 marbles / 5 kids = 0.5 marble per kid
    • 0.25 marbles / 0.5 kids = 0.5 marble per kid, but there’s only one half a kid with a quarter of a marble in this example.
  • TxzK@lemmy.zip
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    4 months ago

    0.5 = 1/2, 0.25 = 1/4

    0.25 / 0.5 = (1/4) / (1/2) = 1/4 * 2/1 = 2/4 = 1/2 = 0.5

  • Iron Lynx@lemmy.world
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    4 months ago

    In case people would like it demonstrated,

    0.25/0.5

    = 1/4 ÷ 1/2

    = 2/4 ÷ 2/2

    = 1/2 ÷ 1

    A÷1 = A, therefore 0.25/0.5 = 0.5

    Alternatively, (a/b)/(c/d) = (a×d)/(b×c)

    1/4 ÷ 1/2 = 1×2 ÷ 4×1 = 2/4 = 1/2

    • Iron Lynx@lemmy.world
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      4 months ago

      And before any pedants crawl out of the woodwork, there are a load of implied brackets, at the spaces.

    • raspberriesareyummy@lemmy.world
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      4 months ago

      y/x = x with y = x*x because 0.25 is 0.5 squared.

      from the “wow factor” it’s the same as writing: 9/3 = 3 - not very wow at all

    • AFK BRB Chocolate@lemmy.world
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      4 months ago

      Start with the reverse. If you had half a pizza and you wanted to divide it by quarters of a pizza, you’d be able to do it 4 times (there are four quarter slices in a half pizza).

      But with this we’re asking how many half-pizza slices are in a quarter-pizza slice. The answer is that there’s half of one (half of a half is a quarter).

    • myxi@feddit.nl
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      4 months ago

      you’re just doing 1/2 in a smaller scale. it makes most sense logically; it’s actually the numbers that are confusing you.