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.
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.
Dividing any number, except 0, by itself equal 1, so the first part of your argument makes no sense.
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.
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.
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.
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.
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?
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.
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.
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
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.
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.
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
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: =
There are better ways of saying this. You know, polite ways, where you don't come across as an insecure dickhead.
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.
That is really mean. You shouldn't attempt to teach people anything if this is what your mindset is like.
Multiplying by 0.5 halves. Dividing would double the number. 0.25 doubled is 0.5.
Sleep well!
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
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).
you're just doing 1/2 in a smaller scale. it makes most sense logically; it's actually the numbers that are confusing you.
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
And before any pedants crawl out of the woodwork, there are a load of implied brackets, at the spaces.
Every time I see something like this, the comments remind me that common core mathematics is a thing and it makes me sad.
Seriously, why is basic arithmetic worthy of so much discussion?
Just... do the math. It's not complicated math.
I sometimes feel bad about myself cause I didn't get very far into calculus, but then I remember that the average adult has no idea how fractions work.
Huh, thanks for the insight. I've never been able to get my head around weird division like this, and that sounds like a great rule of thumb for thinking about it.
Dividing by a fraction is the same as flipping one it on its head and multiplying it.
0.25/0.5 is (1/4)/(1/2)
To multiply it we'd flip one, either works but for this example I decided to flip the second one: (1/4) * (2/1)
The top half of the fractions (numerators) multiply together, then the bottoms (denominators) multiply together. (1*2)/(4*1) = 2/4 which reduces to 1/2
same as x * .5 = .25
if that somehow helps ya
I suspect people might be getting confused by this because of colloquialisms like "divided in half", "divided in the middle", "divided by two"
things is, math doesn't care about idioms
another area in mathematics that I've seen ppl (myself included lmao) suffer from this is propositional logic. like with the non exclusive nature of the OR operator
but this is all just a wild guess
'A quarter of a half' would be 0.5x0.25 (0.5x1/4 = 0.5/4) and it's not a half. The equation shown is 'a quarter divided by a half'.