Recent comments in /f/explainlikeimfive
John_Vattic t1_iyc64td wrote
Reply to comment by Spadeninja in ELI5 why we first multiply, then add by TheManNamedPeterPan
In your example, you're talking about if the 'agreed language' of math was different, the other answer would be correct. But, if the required answer for this scenario was 7, the actual calculation would be written differently.
It's like if you have a room full of people speaking English, and one dude who only speaks French. It's not that French is wrong, but they're not going to be understanding each other.
carlovski99 t1_iyc60gq wrote
Reply to comment by Megalocerus in ELI5: why is using "goto" considered to be a bad practice in programming? by Dacadey
Or even worse, comefrom https://en.m.wikipedia.org/wiki/COMEFROM
Mike2220 t1_iyc605t wrote
Reply to comment by Sloloem in ELI5: why is using "goto" considered to be a bad practice in programming? by Dacadey
>And without another GOTO to send you back to where you left off, you'll just keep going from wherever you ended up until the program exits or crashes.
jal and jr have entered the chat
sixthghost t1_iyc5rrg wrote
Reply to comment by LordButtercupIII in ELI5 why we first multiply, then add by TheManNamedPeterPan
Exactly. The number 3 in 3 x 5 is not an absolute number but represents the "number of groups". So, it's like 3 groups of 5 (of whatever object) and not "3 objects" and "5 objects".
SifTheAbyss t1_iyc5rk4 wrote
Because multiplication is a shorthand of repeated addition.
2 × 3 is 3 + 3, 3 × 5 would become 5 + 5 + 5, etc.
So 1 + 2 × 3 will give you 1 + (3 + 3). That 1 is just a simple number, it doesn't tell you anything about how many times you're supposed to add 3.
I_Tory_I OP t1_iyc5e5v wrote
Reply to comment by Sea_Pickle_ in Eli5: How big of a problem is the extreme demographic change in Japan? by I_Tory_I
So is every economy built on the idea that the population will grow and never shrink?
Sereaph t1_iyc5dfu wrote
Reply to comment by DragonFireCK in ELI5 why we first multiply, then add by TheManNamedPeterPan
I'd like to delve deeper to clarify this concept. If we're talking PURELY numbers, PURELY mathematics, there IS NO order of operations. The math just *IS*.
For example, 1+2+3 = 6 doesn't happen left to right, right to left, or whatever order at all. 1+2+3 *IS* 6 and it *IS* 12-6 and it *IS* 18/3. All of these terms are just different ways of representing the number 6. They are equivalent, one in the same. Another way to think of it is that ALL the operations are done *at the same time*.
However, human beings aren't instant and we lose track of things all the time. Therefore, we devised the order of operations as an INTERPRETATION of how we observe the math actually works.
But I do want to clarify, this order of operations isn't just an "agreed upon standard" arbitrarily. It's following observed rules. The reason why multiplication comes before addition is because it is already a form of repeated addition.
7 + 3 x 4 is the same as 7+(4+4+4).
If we try it purely left to right, it doesn't make sense.
7+3x4 is not the same as 10x4 because the 3 is *modifying* the 4.
The 3 and the 4 are not separate terms. They are telling us that 4 happens 3 times (or that 3 happens 4 times). The 7 is just another term being added to the evaluation of 3 times 4. So we MUST evaluate 3x4 first.
Here's an illustration:
7 apples + 3 baskets of 4 apples. You don't add 7 apples to 3 baskets. You'd get what, 10 apple/baskets? That doesn't make sense. You add the baskets first (12 apples total), then add the extra 7 apples for a total of 19 apples.
Spadeninja t1_iyc5chh wrote
Reply to comment by BurnOutBrighter6 in ELI5 why we first multiply, then add by TheManNamedPeterPan
Yes I get that
The question is though
When you have thousands of calculations, again in the instance of like a rocket launch, both are correct as long as everyone is on the same page?
And is the order between adding and multiplying is mostly meaningless as long as everyone is using those same calculations?
peter3hg t1_iyc5ca8 wrote
Reply to comment by UncontrolableUrge in ELI5: Why is wales a country but not the states of the US by coolredditfan
It isn't really true to say that Ireland or Wales were what we would consider sovereign countries by modern standards before English rule/colonisation.
Ireland had a vast number of minor and major kingdoms with perhaps only Brian Boru being close to a true ruler over all Ireland, and that for less than 20 years in the early 11th century.
Similarly Wales have various kingdoms and only Gruffydd ap Llywelyn ruled a united Wales, again for a short period of time (less than 10 years) in the 11th century.
What both countries did have was a strong cultural identity across their various kingdoms, especially in contrast to the Anglo-Saxon and Norman ruled majority in England.
BurnOutBrighter6 t1_iyc4yuq wrote
Reply to comment by Spadeninja in ELI5 why we first multiply, then add by TheManNamedPeterPan
Both answers aren't right. On a test only one of those is right, and one is wrong. When you write:
1+2x3
That means "multiply two x three, then add one". There is only one right answer to this. It's 7. 9 is wrong.
If what you actually meant was add 1+2, then multiply by 3, than you have to write it as (1+2)x3, and then the only right answer is 9.
The rules we're talking about here are only about how to write the math so that it means what you intend it to mean (like multiply 2 by 3 then add 1, vs add 1+2 then multiply by 3). But for whatever you write, there's only one right answer.
biggins9227 t1_iyc4gp7 wrote
When you walk your calf muscles help to circulate your blood. Without that movement it increase the risk of blood clots, which can lead to stroke and heart attack.
WebW3b OP t1_iyc4fxg wrote
Reply to comment by shaokim in Eli5, how do contracted Blood Vessels lead to Increased Cardiac Preload? by WebW3b
This proves to be very useful, Lots of Thanks!
boring_pants t1_iyc4ffq wrote
We don't always do that.
If you have (1 + 2) x 3 for example, then you add before multiplying,.
It's just a convention to make it easier to read and write maths. We've agreed that if nothing else is specified, you multiply first. And if you want something else, you can toss a pair of parentheses around it to override that rule.
HMKingHenryIX t1_iyc49b8 wrote
Reply to comment by Schnutzel in ELI5: are megapixels just resolution but for still images? by weakgutteddog27
Thank you for this
nevbirks t1_iyc494y wrote
Reply to ELI5, why do viruses and bacteria have many of the same symptoms when they infect a human? by tapeness
The easiest most simple explanation is that your body will turn up the heat to slow pathogens. The more you sleep the more energy conservation your body has to fight pathogens. Your body will use different nutrients to fight the bacteria. Your body has a type of cell called leukocyte that patrol the blood being on the lookout for anything abnormal. When depleted, you need protein to help replenish. That's why chicken noodle soup is so great. It's easy on the digestion system and has protein in it. Drinking lots of water helps clear our the kidney and liver allowing you to expel the pathogens.
Half_burnt_skunk t1_iyc43kl wrote
Reply to ELI5: Why do people with a few chest gunshot wounds usually die either in minutes to days after receiving necessary surgery? by AltAccAur
The ribs of the human body are there to protect vital organs. Heart, obviously being the most important and lungs being the next. Those require major arteries to pump blood into them for them to function.
Your question is very vague, because there's many types of ammunition that come in different calibers, and different calibers of firearms have a variety of different ammunition. That's a big rabbit hole.
Let's assume someone is hit in the chest with a low caliber firearm with low grain bullets that aren't tipped in any special way. That bullet is passing through bone which in turn becomes its own projectile with force exertion towards your most vital organs.
If you throw in the mix, for instance, hollow-point ammunition, its main intention is to fragment when it hits the initial target. This sends many fragments of the bullet into the vital zone hitting more bones that fragment into the vital zone along side the bullet fragments.
That bullet is also-most likely-taking clothing and other foreign objects with it into the internal organs. All of these can cause a lot more complex operations and increase infection.
bife_de_lomo t1_iyc41vm wrote
Megapixels work for video too, it's just counting all the pixels in an image. 1920 x 1080 would be aboùt 2 million pixels, or 2 megapixels, 3840 x 2160 is 8 megapixels.
Schnutzel t1_iyc41v6 wrote
Yes, megapixels is just resolution. It's just the number of pixels, in millions (mega = million). So a picture with a resolution of, say, 5312x2988, has a total of 5312*2988=15,872,256 pixels, which is just shy of 16 megapixels.
Videos usually have a much smaller resolution than still images, because they take up significantly more space. 4k resolution is 3840x2160 which is just 8 megapixels.
How manufacturers choose to denote resolutions is just a matter of marketing. Historically televisions were marketed using the numbers of lines on the screen (such as 360p, 720p, 1080p), then they switched to the number of columns (such as 4k, 8k). Meanwhile cameras just use megapixels.
hablandochilango t1_iyc3vr3 wrote
Reply to comment by kslusherplantman in ELI5: Why does the water from my kitchen sink taste better than the water from bathroom sink? by [deleted]
Look up the elements of the master sommelier exam
Spadeninja t1_iyc3ukk wrote
Reply to comment by BurnOutBrighter6 in ELI5 why we first multiply, then add by TheManNamedPeterPan
But we arrive at two different answers depending on which path we choose
Like if it was a math test should the teacher mark both correct?
Sorry just trying to make sense of how both answers are right when there should be a right answer you know what I mean?
HarveyH43 t1_iyc3uak wrote
I am very confused about the <. Between 50 and 60 minutes?
BurnOutBrighter6 t1_iyc3kd5 wrote
Reply to comment by Spadeninja in ELI5 why we first multiply, then add by TheManNamedPeterPan
The math itself is fundamental. It would work no matter what convention we chose. The only arbitrary thing we're deciding on here is how to WRITE math so other humans know what you mean when there's more than one possibility.
(more than one possibility for what math you're trying to describe, NOT more than one way that the math itself could go!!!)
bobnla14 t1_iyc374k wrote
Reply to comment by Various_Succotash_79 in ELI5 Are cows constantly producing milk? by ms_myco
That is why a lot of their beef is used in dog food, cat food, other pet food, and canned meats like stews. Long simmerring makes it more tender.
ernirn t1_iyc336n wrote
Reply to comment by Scuka1 in ELI5 How is sitting for prolonged durations (<1hour) bad for your body? by [deleted]
The comparison has a lot to do with the effects on the cardiovascular system. Circulation requires muscle movement to help return blood to the heart (why long periods of sitting puts you at risk for clots). Physical activity also exercises heart muscle, making it stronger for its functions.
ActualGiantPenguin t1_iyc6cek wrote
Reply to ELI5: How were a group of obscure companies the cause of the 2008 financial crisis? by WartimeHotTot
Bear Stearns/Lehman Brothers weren't obscure at all, they just didn't generally offer consumer services except to high-net-worth individuals.
Similarly, Fannie Mae/Freddie Mac were founded to buy mortgages from banks, not to deal directly with consumers. They were both founded by the federal government (hence the similar names) but are private-sector entities.