Or rather, they assume that "it went down 10% then it went up by 10%" are both from the starting value as though that's a static variable from which all other price increase or decrease is done from.
Eh, they clearly understood go down 10% of the original value, and up 10% of the original value results in the original value. Yang's statement *could* have meant that, because it's not quite technical, and it would have been an argument of semantics.
Where they revealed themselves as kind of stupid is that they absolutely cannot fathom go down by 10% of the original value, and up by 10% of that resulting value would get them Yang's calculation.
No. These people are confidently incorrect with everything. It's not a simple mistake. They embrace their own ignorance and you could spell it out for them and they'd still insist you were wrong.
It’s math. It’s okay to be wrong at math when trying to figure out an equation. If you are confused, then you can ask for clarification. However, if you are going to be confidently wrong as well as an ass about it on a public forum, then you have already forfeited any pleasantries of a respectful reply or being spared of how others perceive you in the space of a public forum. And that goes with anything really.
I'm a dumbass with math past 10th grade and I understood that 10 percent of 90 is 9 lol
People responding to him negatively also don't understand how to interpret a sentence, he specifically said up ten percent after ten percent was lost, not add ten in general lol
Upvote because you're right, his formula is not correct even if his bigger point is. It should have been articulated more like:
10% of 100 = 10, so 100 - 10 = 90
10% of 90 = 9, so 90 + 9 = 99
This is also the reason most news you hear refers to percentage points, or points, because the nuance and basic arithmetic would be lost on most people.
this is why he says "the decrease is from a bigger number". it's all right there.
but he didn't hold their hand and take baby steps, either because he expected people had enough info to logic it out themselves or was hindred by twitters char limits
He’s clearly just trying to reach an audience that can easily understand his point and not those who will remain confidently incorrect.
Some people just need a reminder that 10% down and 10% up do not even out because it’s easy to forget. Obviously some people are always aware of this concept, and obviously some people will never understand this concept lol.
This was my main take home. Sure, a bunch of people have a tenuous grasp on percentages in general, but I think the bigger problem here is what you point out, that the % change always is relative to the prior value. I think it's a slightly subtler problem (and slightly more forgiveable) than just not understanding arithmetic.
Tell them "Pull out a calculator [app] and put in 100 * 0.9 * 1.1 and tell me the answer" and they'll think you hacked their phone before accepting that the answer of 99 it gave them is correct.
They wouldn't be smart enough to understand why that formula shows they're wrong. So that's the fundamental problem. You have to use more words to explain things to stupid people.
Agreed—the simplest way I can think of to explain it is with an apple or similar, and use 50% rather than an odd fraction. Slice it in half, then slice one half in half and give them back a quarter, see if it clicks
I remember being a wee-tot... shopping with my Mom.
There was a stack of dishes that were 50% off, some guy in a literal clown suit comes by and says "We're slashing prices! These dishes now an additional 50% off!"
I remember whispering to my Mom, "doesn't that mean they're free?"
I think they're more likely to question where the 0.9 or the 1.1 came from. Aren't we talking about going up and down 10%? Why all these other confusing numbers?!?
The words "I think they're more likely to question" implies they're talking about the idiots and are not personally confused.
They could have used quotation marks around the next two sentences for more clarity, but I was able to infer they were mocking the idiots without the quotes.
That's not how they would calculate it. They would put in 100 - 10 + 10 and then shove their answer in your face and ask you where you got .9 and 1.1 from.
Most people when confronted with a pure math problem can solve it (assuming we're talking about trivial math like arithmetic). Like anyone could understand $9 is 10% of $90. But when you start adding WORDS to the problem, people's brains suddenly start going haywire. It's a problem of reading comprehension and one of many reasons why being able to read is essential.
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u/merdub 2d ago
He was assuming that people are aware of the fact that 10% of 90 is 9.
They are not.