common core math
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Excuse me, but RUBBISH...I was good with math when was young (I'm still not that bad) and I do understand numbers - it's not the way I ever done things...
I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)
Kornfeld Eliyahu Peter wrote:
it's not the way I ever done things
I agree it's weird to anyone with more maths ability than a gnat or gnu, but how often has something like this happened: Green Grocer: That'll be £7.93 please. Me: [Hands over £10] There you go, thanks. Green Grocer: [Hands over 7p] - eight quid [Hands over £1] - nine quid. [Hands over £1] - Tenner! That's the basis of the insano-method
Alberto Brandolini:
The amount of energy necessary to refute bullshit is an order of magnitude bigger than to produce it.
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Can anyone really explain to me what this is all about? So far it seems to be a bunch of hoopla that makes things harder and not better. In all fairness I don't know much about it how all works, but when I see something like this[^] I have to wonder what was being smoked when they came up with it.
Jeremy Falcon
Hmm. It looks like a convenient "shortcut" for doing those operations in your head. It's analogous to how a lot of retailers teach their cashiers to make change for quick cash transactions. I don't like the notion of teaching this as a primary method, without teaching the underlying primitive operations. It's yet another example of "nothing changes". When I was in first and second grade 45 years ago, we were taught the "New Math". I had a really hard time with it, especially subtraction. My mother taught me how she learned how to do it. I got dinged a few times on tests for not following their method, but the teacher couldn't argue with the fact I got the correct answer. A final observation; some kids will learn how to do basic arithmetic well, regardless of the algorithm that is taught. Some will not. It depends somewhat on the kid, but more on the parents. Parents who participate and monitor their kid's education will ensure they learn. Parents who treat school as an all-day babysitter will wonder why their kid is still working as a server at T.G.I. Friday's when they're 32.
Software Zen:
delete this; -
It's not Maths; it's counting. Everyone can count, so it's really easy. Now subtract 7 from 472326598458412365452131236525897456321452453698736985215457. Call me next week when you're done.
I wanna be a eunuchs developer! Pass me a bread knife!
How about I use a calculator, and don't call you. :)
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Kent Sharkey wrote:
it's basically the way everyone figures out change
Except for that it isn't.
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Kent Sharkey wrote:
Doesn't that mean that they're now trying to override the way they already learned?
Yes. One of the biggest problems in the US is the constantly changing curriculum requirements. This means that what you taught in 6th grade might be re-taught in 7th, or that the new 7th grader is expected to have been taught something different in 6th grade as a the basis for what they are going to learn in 7th grade. My son, who was getting a math-teaching degree at SUNY New Paltz, explains that the curriculum can literally change 2 or 2 times in a school year. Furthermore, because of "No child left behind" and other rubbish (and we can't blame Bush, the tenets of NCLB goes back to the 50's, if not earlier actually) the teacher MUST teach to the curriculum, paced at whatever some bureaucrat decided, because the teacher is graded on how the kids score, so teaching does nothing more than attempt to teach how to pass a test. Every teacher I've talked with hates this system, but what do you expect from a curriculum that was decided in a national conference where all the decision makers were business people, and only one, yes one, I kid you not, teacher was invited to said conference. This country is so FUBAR. Sadly, when I talked to a couple college kids from France, they say their educational system is even worse!!! Marc
Imperative to Functional Programming Succinctly Higher Order Programming
Marc Clifton wrote:
Every teacher I've talked with hates this system, but what do you expect from a curriculum that was decided in a national conference
I think that's a large part of it. Teachers hate it and students will also as it is incorporated, but this is the way to force more national standards -- central control -- upon every little city out there. Plus this way we can teach all the children to pull the same levers. "I hear and and obey..." :D No need for thinking, that's for the smart people.
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Can anyone really explain to me what this is all about? So far it seems to be a bunch of hoopla that makes things harder and not better. In all fairness I don't know much about it how all works, but when I see something like this[^] I have to wonder what was being smoked when they came up with it.
Jeremy Falcon
If I were inventing a program called Common Core Math it's purpose would be to set standards across (whatever entity) that are expected to be met to be considered as having adequately mastered various levels mathematics. The purpose would be to eliminate various schools districts (public, private, parochial) from letting even more innumerate cretins loose on society. One needs to add, subtract, multiply, and divide. Understand some rudimentary geometry and be able to apply said knowledge to problem solving. Problem types would be realistic in terms of applicability to what passes for real life situations and be devoid of fluff. You need to be competent to move on. The implementation I would leave to those on the teaching side. That, and the assertion that the occasional sacrifice of troublesome students benefits classroom discipline, may well be why I didn't become a teacher. Or maybe why I should have?
"The difference between genius and stupidity is that genius has its limits." - Albert Einstein
"As far as we know, our computer has never had an undetected error." - Weisert
"If you are searching for perfection in others, then you seek disappointment. If you are seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010
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Hmmmm... 38 - 25 = 13 , and 100 - 13 = 87 , so 287 .
I'd do 300 - (38 - 25) without even thinking about it. The common core method is not something that should be taught. It is something that should be learned via the ah-hah moments that occur inside your head when you get a good handle on arithmetic. If you understand numbers, the tricky methods will come naturally.
We won't sit down. We won't shut up. We won't go quietly away. YouTube and My Mu[sic], Films and Windows Programs, etc.
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It's not Maths; it's counting. Everyone can count, so it's really easy. Now subtract 7 from 472326598458412365452131236525897456321452453698736985215457. Call me next week when you're done.
I wanna be a eunuchs developer! Pass me a bread knife!
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It's not Maths; it's counting. Everyone can count, so it's really easy. Now subtract 7 from 472326598458412365452131236525897456321452453698736985215457. Call me next week when you're done.
I wanna be a eunuchs developer! Pass me a bread knife!
string s = "472326598458412365452131236525897456321452453698736985215457" ;
int i = s.IndexOf ( "7" ) ;
s = s.SubString ( s , 0 , i ) + s.SubString ( s , i+1 ) ;(Or something like that.)
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Kent Sharkey wrote:
Here's a post about the merits of it[^], or at least why it's not really that bad.
I see how using the base as a reference point is a good thing for mental math; I do that already. But they way they implemented it is just retarded. In the case of
325 - 38, why not just do something more like325 - 40 + 2to get the answer? Or hell even(325 - 25) - 40 + 25 + 2? You get the benefit of it being easier mentally without all the extra crappy steps.Jeremy Falcon
It seems to me that those of us who are really good at mental arithmetic have always solved problems differently depending on context. The reality is that we rarely use long subtraction, but use all manner of shortcuts. It's a little like programming: We take a first look at the problem; determine a method, based on experience; we implement. As we learn new tricks and put them into practice we add them to our list of methods, sometimes replacing old ones (I still, rarely, use DOS batch file coding!) The trouble with teaching maths using that approach is that kids need to start learning one way. If an experienced maths teacher says that they found it easier to teach this way, I'd take his word for it. Bad explanations and bad examples only serve to reinforce our prejudices ("That's not how I was taught to do it!") As programmers, I would hope that we'd be open to consider new techniques? I do think that there is merit in learning the "granny" method too, because sometimes the "simpler" tricks break down and the problem is too complex to solve with a hack!
Life is like a s**t sandwich; the more bread you have, the less s**t you eat.
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Um...you probably should have chosen a more difficult problem. :p
We won't sit down. We won't shut up. We won't go quietly away. YouTube and My Mu[sic], Films and Windows Programs, etc.
That's the point. Using the common-core-counting method, it would take forever! Not using the common-core-counting method, it takes as long as it takes to see what the last digit of the number is.
I wanna be a eunuchs developer! Pass me a bread knife!
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How about I use a calculator, and don't call you. :)
If you need a calculator for that, you should call a private arithmetic tutor.
I wanna be a eunuchs developer! Pass me a bread knife!
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I was going to pipe up with the same explanation that everyone else did, It's a good way to do subtraction in your head. I learned that and more as a child. The common core doesn't seem that weird to me, but it sucks that they don't have any physical materials to work with like I did. For example this is one way I learned multiplication: Checkerboard[^] This is what I worked with for addition: Bead frame[^]
Curvature of the Mind now with 3D
I can't watch YT videos at work... oh the tease! :laugh:
Jeremy Falcon
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I think that is stupid way to do math. Sorry, but that is how I feel.
No need to apologize man. I like the premise personally, I just don't particularly see how the implementation is good.
Jeremy Falcon
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It's not Maths; it's counting. Everyone can count, so it's really easy. Now subtract 7 from 472326598458412365452131236525897456321452453698736985215457. Call me next week when you're done.
I wanna be a eunuchs developer! Pass me a bread knife!
Mark_Wallace wrote:
Now subtract 7 from 472326598458412365452131236525897456321452453698736985215457.
42326598458412365452131236525894563214524536983698521545Tada!!Jeremy Falcon
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Hmmmm... 38 - 25 = 13 , and 100 - 13 = 87 , so 287 .
Well of course. But for me 38 - 25 takes more effort than fiddling the numbers in my head, either by adding or subtracting to reach easier to work with numbers, or breaking it down into smaller sums, for example
((30-20) + (8-5))(although that requires me to remember more numbers at a time). If I had to do mental arithmetic more than few times a month (beyond counting change) than perhaps I'd have an easier time with it. I'd also like to point out that I don't sit there and think "Perhaps if I add two or three here, and then..." the route to the answer comes without much thought. -
Can anyone really explain to me what this is all about? So far it seems to be a bunch of hoopla that makes things harder and not better. In all fairness I don't know much about it how all works, but when I see something like this[^] I have to wonder what was being smoked when they came up with it.
Jeremy Falcon
Someone got the idea into their head (Can you smell Ph.D. dissertation?) that students need to understand HOW they got the answer not just the mechanics of getting the answer. Trust me, there are a whole bunch wilder things buried in there. Some bizarre 5th grade thing my wife showed me used area to figure out some calculation that had NOTHING to do with area. I agree with the idea of common core, kids in the first grade should know this list of stuff, but there all sorts of problems with the ideas on how to get the information into those little skulls full of mush. Kids don't memorize multiplication tables anymore so they have to figure out each part of a two digit by two digit multiplication problem.
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Kornfeld Eliyahu Peter wrote:
it's not the way I ever done things
I agree it's weird to anyone with more maths ability than a gnat or gnu, but how often has something like this happened: Green Grocer: That'll be £7.93 please. Me: [Hands over £10] There you go, thanks. Green Grocer: [Hands over 7p] - eight quid [Hands over £1] - nine quid. [Hands over £1] - Tenner! That's the basis of the insano-method
Alberto Brandolini:
The amount of energy necessary to refute bullshit is an order of magnitude bigger than to produce it.
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One criticism I have heard a lot about some 'modern' education techniques is the emphasis on 'research'. With the advent of the internet some children are being encouraged to look everything up and 'discover'. In some cases there has been a strong move away from rote learning or the learning of facts. It's certainly something I have seen a bit of, where giving a person a task they rely more on their opinion than on hard evidence. Evidence they can gain by looking in detail at what is happening. My take on it is that you need a solid foundation in basic facts such as memorising simple multiplication tables for simple things. Then extrapolating from those basics to more abstract concepts when you come to things like calculus.
“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
It much older than the Internet - it's called Pupil-Centred Learning and has been around in one form since the 70s to my knowledge, probably longer. This is interesting [^] as it suggest student centred learning can't work until you are about 11 as it requires logic.
Alberto Brandolini:
The amount of energy necessary to refute bullshit is an order of magnitude bigger than to produce it.
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The problem with this system is that it works for subtraction and it is very easy, probably easier then the traditional carry method we all learnt. But that is it. It ONLY works for subtraction. The multiplication method is different, division is different. In other words common core ignores what is common. A + B = C --> C - A = B & C - B = A A x B = C --> C / A = B & C / B = A And as soon as you move into negatives, algebra and real geometry it's useless.
Presenting a reasonable, rational argument? Do you belong on the Internet? ;) Yeah, I was thinking of it in isolation (where I still think as a first method it makes more sense than the traditional method). However, as you point out, other than in isolation it doesn't make sense. Plus - as others have pointed out - this is being taught to older kids who supposedly have already integrated the older method, confusing them. Definitely makes less sense to me now. Fortunately, no kids in the system.
TTFN - Kent
