- cross-posted to:
- funny@lemmy.ml
- cross-posted to:
- funny@lemmy.ml
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Yang botched it by chaining
=wrong.100 − 10 = 90 + 9 = 99
❌ cringe
100 − 10 = 90
90 + 9 = 99✔️ based
Don’t they teach math in the US anymore? Or do you get a pass on basic subjects if you are on the football team?
Practice is important. People definitely learn this level of math, but not using it for years dulls the senses. On top of that, lots of people scrape through school doing the bare minimum. (Not always their fault of course. Not everyone has ample opportunity to excel in school due to a variety of things.) From what I hear, the bar for graduating high school is not incredibly high, so people like this don’t surprise me.
Knowing basic math (and sometimes a bit more) is quite useful in life. I am currently having a beef with my bank who tried to cheat me out of a larger sum. But I know the correct methods and the correct rates, and, of course, the contract. And obviously, it really pisses them off that someone even does the calculations…
No they definitely teach math but unfortunately math is kind of useless when they don’t teach critical thinking.
Because then people blind themselves with their own bias and refuse to actually critically think about what they’re reading and realize that they misread it or misunderstood it.
Goddamn I’m glad I was in Gifted
These people have no fucking clue what they missed
I was lucky to go to relatively good public schools and do some extra classes as well. It’s unfortunate that a good education is locked behind being wealthy enough to live in a good area and additional instruction outside of school, sometimes. This is one of the things that shows that people are not on a level playing field in the US.
It’s so getting worse too as we continue to defund public education so parents are forced to send their kids to private school, or worse, home school them.
It’s a problem non-white Americans have been talking about for a real long time now. If only we could leverage the Department of Edu- oh
Tis why they got rid of it, eh.
You get a pass on pretty much every subject because the school’s interested in churning out worker drones rather than thinkers. Do this long enough and you get Trump supporters.
Heck, for a while, we insisted on passing kids no matter what so they weren’t “left behind”.
They teach math from like 6th grade up as if every middle schooler in the land is going to grow up to be a sweater wearing chalkboard writing mathematician when they grow up. It’s taught as a series of arbitrary rules to follow. Here’s some squiggles, and now you do this to the squiggles. NO you don’t do that to the squiggles, do you want to be a ditch digger you fucking waste of sperm. You do THIS to the squiggles. Can’t you FUCKING tell the difference you little cuntpuke? You use the Crendicative property of intiplicity. No, it’s not five, it’s negative three. It’s obviously negative three, What idiot would get five? I know you got five and not some other number because this is designed to be a trick question. There’s only one point in this big long procedure that matters, if you decide correctly you get negative three, if you decide incorrectly you get five. And you got five.
They do this to you for your entire adolescence.
So you’re bad at maths and extremely bitter about it. Ok.
I actually learned math in physics class. Because in physics class, the equations mean something. They represent a relationship between things that you can grasp. There are built-in sniff tests. You can go “Wait, the ball rolled off the table and then…started moving toward the ceiling? That’s not right, where did I…Oh I subtracted a negative number, I should have added a negative number.”
From Kindergarten up to about middle school, they teach by practical example. “You have two apples, and you buy two more, you have four apples.” “If you have two pizzas, each cut into 8 slices, you eat 5 slices from one and 6 slices from another, how many pizzas do you have left?” That stopped entirely in middle school to be replaced with “Here are abstract rules to apply to abstract numbers, and instead of explaining why here are paragraphs of “proofs” written in a logic system we won’t teach you anything about and therefore mean nothing to you, memorize it verbatim so you can write it on the test.”
Yeah I’m not compatible with math class as I’ve seen it taught. I can do math when it means something. Arbitrary meaningless bullshit busywork full of gotchas? Nah, I’m not doing it.
My third grade teacher told me that negative numbers didn’t exist because having less than zero is impossible. I think I’m justified in being bitter about my education.
Yeah you’re right that they act like everyone’s gonna be a pure mathematician with only abstract applications. I think test standards have kinda fucked with their expectations. I’m sorry you had bad math teachers. Many of them suck at explaining the subject and act like dicks. Get enough of them in school and it’s easy to lose interest in something that’s extremely practical to know later in life.
No, they don’t.
Yeah he totally cooked Yang. That guy has NO IDEA where the 9 came from.
Both sides are right in a way. It just depends on what you’re comparing the +/-10% to
Percent increase/decrease is
change/original.This is clearly about the US stock market crashing. In that case it’s always the days gain/loss, in which case Yang is the only person who is right.
This is important because a lot of people saw “down 10%” and now “up 10%” without realizing that’s still day over day loss.
While the idea put forward by him is correct, stating that 100-10=90+9=99 is just entirely incorrect, hence why I’m saying they’re both somewhat correct
That is the difference between percent and percentage points.
TBF Yang really did write the equation in the sloppiest way possible.
Like I know what he MEANS but no math professor in the world would let this shit slide.
Yeah if you put it:
100 - (100 x 0,1) = 90
90 + (90 x 0,1) = 99
It comes quite obvious. And I know the brackets are redundant, but my coder mind forces brackets to all math formulas for readability.
Was it on purpose, maybe.
Decimal commas ain’t 'merican: you’d totally throw them with your weird euro math.
Even
100 - 10% = 90
90 + 10% = 99
Works better than what he did, because that’s how you’d enter it on a standard calculator.
100 - 10/100 ≠ 90
I’m not a fan of this at all and wish people would treat percentages as if they were a unit. x% is x of y per 100 total.
x% = x yi / 100 ytotal
Where yi is the species in question.
My cup is 90% full: My cup contains 90 unitswater / per 100 unitscup
This is why I don’t like Baker’s percentages. I guess it makes sense, because it’s still per cent, but they’re mixing the meaning used practically everywhere else these days.
50% water for baking isn’t 50 unitswater / per 100 unitsdough, it’s 50 unitswater / per 100 units**flour**. In my mind that means you have 33.33% hydration, not 50%…
Just feels weird to not express that as a ratio. But I guess it’s a shorthand that works for them :/
Yes I understand all that but I’m telling you standard calculators literally work that way.
Just launch the calculator app on your phone or computer and give it a try, you’ll see.
I never used the percent button, lol. I am not about to start. Something about this doesn’t jive with my soul.
This is very upsetting
Thanks for the heads-up. I would have been happier never knowing haha
The implied brackets. THE IMPLIED BRACKETS!! The horror.
Thanks for the response kind soul
No worries. Yeah I get that it’s a bit weird if you know how to do it properly but it’s actually a fairly helpful trick for quickly calculating discounts, which I assume is the indented use. Remember, calculators were designed for lazy business folks who suck at math.
This is exactly how someone who failed HS math would think about the problem, and conveniently, it just works.
Um you can type like that into a calculator? Any answers please specify an actual calculator vs computer.
Sure can.
And yes I was stunned as well when I learned it, because that’s not how it’s taught in schools. I used to do exactly what the previous commenter did, and then one day I saw some illiterate mouthbreather type it in like that and I was like “nuh-uh, that’s not how that works, gimme that thing and let me show you.” And I typed it in the long and “correct” way, and whaddayaknow? Same result.
But it makes sense when you think about it, calculators were literally invented for business use (and most business people are notoriously bad at math), and one of the most common uses in business is figuring out how much something should cost after applying a discount.
Like an actual calculator or one on the computer?
It works on both. I tried the calculator apps on iOS and Windows and they both worked that way. And if you still have a regular old digital calculator, it should work on that too.
Nope just tried. 7+10% = 7.1 It converted 10% to be 0.1
Most of the ones I’ve used work that way.
An actual calculator or a computer?
Both? The cheap simple calculators I used decades ago would work if I typed
1then0then0then-then1then0then. Granted, I have experience with maybe 3 calculators in my life, so I might have just gotten lucky.
I think of it as
100 x 0.9 = 90
90 x 1.1 = 99
Am I the odd one out?
Percentages for show, decimals for a pro
Shameless plug for Engineering Memes community ported during the great API migration: !engineeringmemes@lemmy.world
100(1-0.1)=90
90(1+0.1)=99
Yes.
But also, Barqs does have bite.
Readability is important. I do the same thing, because just because something is technically correct doesn’t mean there isn’t a better way to do it. I’m very pro-bracket.
It’s twitter, why’d anyone put effort in what they write.
That’s what makes it great bait
Yeah, for idiots
Some bureaucrats in Mexico City tried this years ago.
An important ring road had two lanes in each direction. To increase its capacity, they didn’t actually widen the road; they just repainted the lane markings to turn two lanes into three, and claimed a 50% capacity increase!
Everyone immediately screamed about being crammed together just centimetres apart, accidents increased and the city officials quickly u-turned; they repainted to have just 2 lanes in each direction again.
But they then tried to claim that as that was a 33% decrease, and that because they had earlier increased it 50%, that meant they had achieved a net 17% increase in the road’s capacity!
I have seen this or a variation of this too many times now, saving this for my own meme responses, its too fucking useful.
Brought to you by the same people that can’t explain tides
Tide comes in, tide goes out. You can’t explain it!
For anyone who doesn’t get the reference, here you go
Bread goes in. Toast comes out. It’s a mystery!
Magnets, how do they work?
Nobody knows! Like how you can only see the effects of the wind, but can’t see or explain it.
That knowledge is probably locked away in the 90% of our brain we don’t use.
yeah they think the MOON does it lmfao, everyone knows it’s the CIA’s totally epic wave machine for selling more surfboards 🌊🏄♀️🐟
Ah yes I hate those
And hate windmills
At least they keep the turtles cool
Windmills do not work that way! Good night! 😂
Can’t have a good night, there’s no power because windmills only work in the day! smh
Please watch S04E08
Any respectable man of science will tell you that due to thermodynamics, the windmills actually result in a net heating effect
Not even close to that anyway, the dow jones for example went from 44k to 37k back up to 40k. Still hasn’t even regained half the value it lost.
I might as well throw the same comment in here. You learn this pretty quickly when you bet on meme stocks. Down 90% then up 100% I can assure you, you are no where near where you started.
Same with crypto. You’ll get a notification something went down 10%, then up again 10%, but if you zoom out you see it’s just been slowly going down on average since the last huge spike.
I thought this was c/funny not c/deeplyconcerning
You want concerning…talk to teachers about gen alpha. They can’t read well, their grammar sucks, they can’t use PC’s, they’re super gullible and believe/want to purchase whatever online influencers tell them to, and just believe whatever pops up at the top of their search result or AI says.
I am not convinced Alpha is unique in their gulliblity and think we should all be hesitant to believe anything we hear online about how bad ‘the youths’ are.
I’m a couple generations back. Every generation seems to talk crap on the next, but these kids are different.
pegglegg back in fifth grade: ‘why i need to learn this math stuff. i aint never gunna use it’
It’s not that you will regularly have a calculator in your pocket
Checkmate
you still need to know what buttons to push on the magic box, and in what order…
Yeah the “checkmate” was supposed to signify that irony
“It’s not like you’ll regularly have a little box in your pocket with access to the sum of all of the knowledge in the world but you’ll have to sift through an equal amount of incorrect knowledge and have the ability to differentiate the two.”
And how long to push them.
That kind of math didn’t start for me until letters started showing up in it. This is basic shit though!
It’s only the same if it’s up 10% compared to the original number. It all depends on your time period, you could be up 30% compared to 7 years ago.
Tesla stock prices are good example of this. They are down ~50% since december and up ~70% since lowest point in april last year.
This is why in forecasting and time series analysis is used the log difference, a 10% increase or decrease on the log scale gives you the same value being added or removed.
Yes, that requires a reference value to be decided upon beforehand.
Not really, you do t=n and t=n+1, for n= 1, 2, 3 for a quick view on volatility.
Then ypu look up for correlations between e[t=n | t= 0, t= 1…] for different Ns. For more I would need to check out my notes
Oh I was imagining something entirely different. Like a simple logarithmic scale of a signal, I do not know anything about time series analysis. Should’ve kept my mouth shut
