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Hieronymous Alloy posted:I have no idea how the "new" system is supposed to work; that looks more like numerology than arithmetic to me. Is there a link somewhere to a basic guide to the "new" system? I've talked about it a bit in the forwarded email thread but I'm on a phone right now so I can't look it up. In short, you're starting with the small number and then adding easy numbers until you get to the big one. It's interesting because it allows you to perform subtraction by using only addition. Try it with 100001 - 99999. With the old fashion way you've got a difficult problem. With the new way, you add 1 to 99999 to make 100000, then add 1 again to get to 100001. 1+1=2, therefore 100001-99999 =2
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Apr 16, 2014 00:06
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It is also a good way to teach math as something that involves number sense and critical thinking as a problem solving tool instead of discrete brute force algorithms.
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Apr 16, 2014 00:08
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StandardVC10 posted:Arrays of objects in rows and columns were how I learned to multiply 15 years ago.
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Apr 16, 2014 00:10
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Mercury_Storm posted:I've seen some friends quoting Victoria Jackson posts on facebook about the new methods of teaching things like subtraction under common core. Even considering the source, the method shown did actually seem needlessly complex, and I don't really get the point of the change if this is indeed what's actually happening. This is similar to what I received only it had a bunch of cubes and poo poo thrown in for good measure. I see what they're trying to do but it really is making the problem needlessly complex. I guess this is a bad place for a Common Core derail but i just know that a lot of this coming from a "those drat Democrats/liberals place" - especially from the Father in Law. I can;t even figure out where this started.
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Apr 16, 2014 00:13
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OAquinas posted:For a simple problem like 32-12 it's not really beneficial to use the "new" math system. For 2631-1783, on the other hand, it helps simplify the process--you're not "borrowing" anything, and you're largely dealing with round numbers. It doesn't actually work better for most kids though. It's also been around for a very long time, long enough to know it provides no meaningful benefit.
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Apr 16, 2014 00:15
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This image is pretty judgemental in how it labels the methods 'old fashioned' and 'new' as if new is this usurper method which is unnecessarily confusing. In reality, both methods (and more!) are taught, in which case you can ask why you would only teach one way to solve a problem. Did you only learn how to use one tool in shop class back in the day? Ghost of Reagan Past posted:Some of us were brute-forced into memorizing a table that was never explained, I remember my multiples via Schoolhouse Rock most of the time. https://www.youtube.com/watch?v=aU4pyiB-kq0&t=1s boner confessor fucked around with this message at 00:18 on Apr 16, 2014 |
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Apr 16, 2014 00:15
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moths posted:Common core is loving weird! posts always show the homework work out of context. The context is literally a class that explains that homework. I can also only assume that the homework examples being very easy to do using the "old" method is so that you can check your work and see if you're doing the other one properly, so you can practice the method itself. Kind of like how in the later calculus classes (at least the ones I took) the answers were usually single-digit or some multiple of pi, so if you ended up getting something like 267.443, you had a pretty good hint to go back and check your work.
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Apr 16, 2014 00:16
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Install Windows posted:It doesn't actually work better for most kids though. It's also been around for a very long time, long enough to know it provides no meaningful benefit. I'd be interested in reading the study that informed this post. Thanks in advance for posting it.
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Apr 16, 2014 00:21
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Ghost of Reagan Past posted:The idea is pretty straightforward. Let's think of it algebraically: 32-12=x. How do you find x? One way is to figure out what you need to add to 12 until you reach 32. So you can think of it like 12+x=32. Anyway, the easiest numbers to work with arithmetically are usually multiples of 5 or 10, so you first 12+3=15 (a multiple of 5). Then you want to get to the multiple of 10, so 15+5=20. Do it again until you get to 30, so 20+10=30. Since if you add 5 or 10 to 30, you overshoot your mark, so you get 30+2=32. How, then, do you get from that to 20? Easy: add up the numbers you added to get to 32, which is 3+5+10+2=20, an even more straightforward arithmetic problem. On an easy problem like that it's absolutely extravagant, but when you get to big-rear end arithmetic problems it helps a great deal. Try doing some complicated 21009341043-184817412 the way we all learned; it's just absolutely monstrously complicated. This other method makes it much more approachable. Okay, so in the way we learned it growing up it'd look like this: 21009341043 - 184817412 = 20824523631 And any time the number on the top was smaller than the number on the bottom, you'd borrow 1 from the one to the left to make it 10+the number so that you could subtract again. In this case you have to do it two numbers in a row sometimes. Under the new way it would look more like this: 21009341043-184817412=________________ 184817412 + 3 = 184817415 184817415 + 5 = 184817420 184817415 + 80 = 184817500 184817500 + 500 = 184818000 184818000 + 2000 = 184820000 184820000 + 80000 = 184900000 184900000 + 100000 = 185000000 185000000 + 5000000 = 190000000 190000000 + 10000000 = 200000000 200000000 + 800000000 = 100000000 1000000000 + 20000000000 = 21000000000 21000000000 + 9341043 = 21009341043 Then 3 +5 +80 +500 +2000 +80000 +100000 +5000000 +10000000 +800000000 +20000000000 +9341043 =20824523631 Yeah, okay, that works. It's a lot of written down steps, but I can see how it works. With giant numbers like that it can be a thing. I couldn't do that in my head in either fashion, but I think I get it. And in all honesty, the first method is just a lot of little calculations anyway, so showing work would have a lot of steps in it as well.
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Apr 16, 2014 00:26
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kik2dagroin posted:Backstory https://www.youtube.com/watch?v=YHPQYqazXfM Sure, let's break down the video of Hillary Clinton (D) in detail and draw conclusions based on things she didn't actually say...
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Apr 16, 2014 00:35
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What is up with the lamestream media targeting me? I didn't say what they said that I said *goes on for about 2 hours saying exactly what he claims he didn't say*
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The new math method is intuitive enough that it resembles analysis for constructing the most efficient approach to a problem, however the examples people tend to use in images that get passed around end up taking what resembling a child's approach by small yet increasing chunks of numbers. Obviously 32-12 is going to be greater than 2, or 3, or 10, just by the simple processing of the highest order digit, so the explanatory approach makes it seem far more convoluted than it actually is processed. Furthermore, you wont go through each stupid 10-9 carry the 1 bullshit for 100001-99999 when you can see immediately that the numbers are so similar so you quickly process the difference using the new method. Mental processing of the new method, from someone who was only formally taught the classical method, makes the end result just seem like a muscle memory hybrid of the two. What I'm interested in is if anyone who is proficient at mental calculations actually goes through the classical method step by step in their head or is it just the near-automatic processing resembling the new math method due to the latter being leaps and bounds more efficient by allowing one to effectively disregard the seemingly vast quantities in most equations through reduction to a more base problem: fore example randomly typing some 4-5 digit values to a problem i get 15893 - 7450 we can quickly recognize that 7450 is not even half of the higher value, so the actual problem is quickly formulated as 15893-14900 + 7450, which is quickly reduced to 1000-7+7450. I might be able to say that im helped by a neat lower value that is more easily doubled mentally, but even if you're writing the problems out on paper rather than calculating mentally you can cut a lot of needless calculation time out by reducing it to things that are readily remembered or more easily mentally calculated.
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Apr 16, 2014 00:40
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I laughed so hard I'm sore. I work at an airport (though not for an actual airline, I work very closely with them, though) and watching the push-back tug driver get the angle wrong on parking the aircraft and having to do a do-over was incredibly hilarious. The men and women who drive those push-back tugs are supposed to be like tractor-trailer drivers. They are supposed to be able to calculate the angles in their heads as they perform their jobs and never waste movement time or risk equipment damage by getting the angles wrong. By itself, I realize it's not SO funny, but with that music playing and everyone cheering, suddenly it's sheer magic of incompetency. O, Mitt 
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Apr 16, 2014 00:42
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Someone explained to me it was meant to explain to kids how to use programming concepts like a while-do loop.
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Apr 16, 2014 00:50
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mr. mephistopheles posted:I'd be interested in reading the study that informed this post. Thanks in advance for posting it. There's never been any study that shows it does better, and basic test results do not improve in districts that have done it. It's been around since the 80s, so if there were positive results from the way of teaching they would be apparent by now.
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Apr 16, 2014 00:51
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Install Windows posted:There's never been any study that shows it does better, and basic test results do not improve in districts that have done it. It's been around since the 80s, so if there were positive results from the way of teaching they would be apparent by now. Sources on any of this?
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Apr 16, 2014 00:55
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mr. mephistopheles posted:Sources on any of this? Give me sources that it's had a meaningful and consistent long term positive effect. No one needs a source for the sky not being plaid.
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Apr 16, 2014 00:59
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Install Windows posted:Give me sources that it's had a meaningful and consistent long term positive effect. No one needs a source for the sky not being plaid. Of course not. Another quality post by the #39 most ignored poster of all time.
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Apr 16, 2014 01:09
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Install Windows posted:There's never been any study that shows it does better, and basic test results do not improve in districts that have done it. It's been around since the 80s, so if there were positive results from the way of teaching they would be apparent by now. Fishmech's kryptonite: things that have "been around" but that you are mentioning now, after they've already existed for a period of time. Follow up to source request: "reality," "recorded history."
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Apr 16, 2014 01:17
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I'm so old fashioned I use my fingers to carry the remainders.
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Apr 16, 2014 01:21
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Install Windows posted:Give me sources that it's had a meaningful and consistent long term positive effect. No one needs a source for the sky not being plaid. That's some pretty stellar circular logic.
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Apr 16, 2014 01:36
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quote:The image example just looks like a combination of this objective: "Understand subtraction as an unknown-addend problem. For example, subtract 10 – 8 by finding the number that makes 10 when added to 8." And this objective: "Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on; making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 - 8 = 4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13)." Note that these are objectives for first graders who might understandably benefit from being able to look at math problems from many different angles and from a more comprehensive understanding of the relationships between addition and subtraction for the next dozen years of learning. Just saying "hey, we substitute a ten to the ones place because shut up that's how we do it" doesn't seem to convey those relationships as well. e: Hell, that's even the explicit goal given on the site: "Students develop strategies for adding and subtracting whole numbers based on their prior work with small numbers. They use a variety of models, including discrete objects and length-based models (e.g., cubes connected to form lengths), to model add-to, take-from, put-together, take-apart, and compare situations to develop meaning for the operations of addition and subtraction, and to develop strategies to solve arithmetic problems with these operations. Students understand connections between counting and addition and subtraction (e.g., adding two is the same as counting on two). They use properties of addition to add whole numbers and to create and use increasingly sophisticated strategies based on these properties (e.g., “making tens”) to solve addition and subtraction problems within 20. By comparing a variety of solution strategies, children build their understanding of the relationship between addition and subtraction." Sometimes "getting the answer" isn't the goddamn point of an exercise. Mo_Steel fucked around with this message at 01:49 on Apr 16, 2014 |
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Apr 16, 2014 01:41
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Apr 16, 2014 01:49
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Rush posted:It's just sick. So now we've gotten to the point, ladies and gentlemen, where the top 1% now pay nearly 30% of all federal tax revenue, not just income tax, all, 30% of all federal tax revenue is now collected from the top 1%. Funny because according to 2010 numbers the top 1% wealthiest Americans owned 35.4% of all wealth. Such a burden possessing that much cake to both have and eat.
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Apr 16, 2014 01:53
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Mo_Steel posted:The image example just looks like a combination of this objective: Well looking at it that way does put a lot of the facebook whining about this issue in perspective. Though I have relatives who have kids going through this exact section, and even that doesn't stop them from freaking out when their kids come home with homework like this. One wonders how much attention these parents are actually paying to what their kids are supposed to be learning, though.
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Apr 16, 2014 02:13
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So basically it's good for any problem that involves carrying the one, and kinda tedious for any problem that doesn't?
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Apr 16, 2014 02:31
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Isn't this all supposed to get kids to the point where they're comfortable playing with numbers? I mean the picture is hugely disingenuous, it doesn't show any of the work most people's brains do when subtracting 12 from 32. The problem is, will it be consistently taught as a way to make kids play with numbers? Or are they going to teach the method by rote without looking for the insight? Again we come back around to the need for well-paid, highly qualified teachers to interpret and teach the standards.
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Apr 16, 2014 02:35
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HootTheOwl posted:So basically it's good for any problem that involves carrying the one, and kinda tedious for any problem that doesn't? Sort of. Not really. The first time it showed up months ago I thought it was kind of pointless before realizing I do a lot of my mental arithmetic like that without ever having thought about it. It's not really a replacement for the 'old' method, it's just a supplement that lets kids think of problems in a different way.
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Apr 16, 2014 02:36
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SedanChair posted:Isn't this all supposed to get kids to the point where they're comfortable playing with numbers? I mean the picture is hugely disingenuous, it doesn't show any of the work most people's brains do when subtracting 12 from 32.
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Apr 16, 2014 02:48
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Ghost of Reagan Past posted:Nah, if you let kids play with numbers they might think math is interesting. We gotta beat out the childhood wonder at the weird patterns and things you can do with numbers and make them hate it so that there's more generations of mathophobes who can barely do basic arithmetic and need specialized apps on their phone to calculate tips. Next you'll want me to count back change by adding up from the closest dollar. Paying for a $11.62 order with a $20 means I give back a $5 ($16.62) 3 $1s ($19.62) 1 Quarter ($19.87) 1 Dime ($19.97) and 3 Pennies ($20.00) for a total of $8.38? What am I, Dean of Mathematics at Yale? 
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Apr 16, 2014 03:20
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Mo_Steel posted:Next you'll want me to count back change by adding up from the closest dollar. Paying for a $11.62 order with a $20 means I give back a $5 ($16.62) 3 $1s ($19.62) 1 Quarter ($19.87) 1 Dime ($19.97) and 3 Pennies ($20.00) for a total of $8.38? What am I, Dean of Mathematics at Yale? You laugh but... 
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Apr 16, 2014 03:24
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This reminds me of one of the hallmarks of forwarded e-mails and bitching about kids these days. "These drat kids need a machine to calculate change for them!?!" They don't realize that mental math is A) slow B) less reliable than computers which are specifically very good at this kind of rote calculation. No matter how well a human can calculate change. The computer is always going to be more accurate unless every single cashier is necessarily going to need to be Rain Man.
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Apr 16, 2014 03:26
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Hieronymous Alloy posted:I have no idea how the "new" system is supposed to work; that looks more like numerology than arithmetic to me. Is there a link somewhere to a basic guide to the "new" system? That image deliberately obfuscates it. computer parts posted:You laugh but... In China (where they don't have 25 分 coins, but still...) people will get annoyed with you if you DON'T do this. edit: maybe not going up a denomination, but paying so that the change is simple. VideoTapir fucked around with this message at 03:44 on Apr 16, 2014 |
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Apr 16, 2014 03:29
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computer parts posted:You laugh but... Alright not gonna lie I got near retarded levels on all my math tests so it legit took me a good moment of thinking to get that total too. How bout give me 2 and I'll just give you a dime and a penny and we'll call it a day?
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Apr 16, 2014 03:38
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ErIog posted:This reminds me of one of the hallmarks of forwarded e-mails and bitching about kids these days. "These drat kids need a machine to calculate change for them!?!" They don't realize that mental math is A) slow B) less reliable than computers which are specifically very good at this kind of rote calculation. No matter how well a human can calculate change. The computer is always going to be more accurate unless every single cashier is necessarily going to need to be Rain Man. Eh, I've worked registers before and generally it's faster for me to do the math as I'm removing the change out of the drawer than it is for me to stop and look up at the monitor between denominations. Particularly if after I entered their order they suddenly find a quarter to reduce the change volume given to them, because now the machine isn't going to be accurate. Granted, registers are very frequently just going to automated dispensers now which totally eliminates the need to begin with for the more complicated coinage portion; change in dollars are utterly simplistic to do. Tatum Girlparts posted:Alright not gonna lie I got near retarded levels on all my math tests so it legit took me a good moment of thinking to get that total too. How bout give me 2 and I'll just give you a dime and a penny and we'll call it a day? I'd much rather have a $5 and a quarter back. gently caress pennies.  Then again I wouldn't be carrying 4 pennies around to make 0.14 so gently caress it just throw it in the change jar and I'll take the dime.e2: For that matter just give the guy $2.14 instead of $7.14 and you just get a quarter back and don't have to exchange a $5 bill back and forth, what the gently caress Dilbert. 
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Apr 16, 2014 03:40
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Mo_Steel posted:e2: For that matter just give the guy $2.14 instead of $7.14 and you just get a quarter back and don't have to exchange a $5 bill back and forth, what the gently caress Dilbert. That's engineer thinkin' for ya.  Plus most cashiers hate giving back quarters because they're always in short supply.
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Apr 16, 2014 03:49
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Were people still using mechanical cash registers when that Dilbert was written? Because everyone knows the venerable IBM 4694 with automatic change calculation was released in 1991.
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Apr 16, 2014 03:52
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Loving all this education/math talk in this thread about Right Wing Media.
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Apr 16, 2014 03:53
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Mineaiki posted:Loving all this education/math talk in this thread about Right Wing Media. If it's any consolation, the right wing will stomp their feet and yell that China is overtaking us in math test scores but cut every cent they can for education they can get away with.
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Apr 16, 2014 04:03
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Mineaiki posted:Loving all this education/math talk in this thread about Right Wing Media. I think right wing media's portrayal of new math standards as inappropriate or not useful belies a lack of understanding of the objectives of said standards and of the real-world applications of said math procedures when doing even simplistic tasks common to adults like figuring change or tips or estimating sales tax. Which was the context this topic came up one whole page ago. Perhaps you would be interested in discussing the portrayal of education standards in right wing media as well? Though maybe you don't feel Victora Jackson qualifies as right-wing media. I could concede that point.
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Apr 16, 2014 04:04
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The school I went to must have been teaching the New English because the term I learned was "old-fashioned". E: the only reason conservatives bitch about this stuff is because common federal education standards takes away the legitimacy of religious education/homeschooling. That's it.
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Apr 16, 2014 04:10
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