Common Core Math

Discussion in 'Physics & Math' started by Kittamaru, Jul 23, 2014.

  1. Kittamaru Ashes to ashes, dust to dust. Adieu, Sciforums. Valued Senior Member

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    http://www.thefederalistpapers.org/...solved-the-old-way-versus-the-common-core-way

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    Okay... what? I mean... I THINK I see how they are doing this:

    32-12 = ??

    Take 3 from the 32, add it to 12, and you get 15 and 30
    Take that fifteen - subtract 5 more from the 30 and add it to 15 and you get 20 and 25
    Subtract 10 from the 25 and add it to the 20 and you get 30 and 15
    Subtract 2 from the 15 and add it to 30 and you get 32 and 13
    Add the numbers you moved - 3, 5, 10, and 2 - that adds up to 20.

    But... seriously, what? What kind of convoluted bullshit method is this? To think... they are apparently teaching children this method for addition and subtraction? REALLY?
     
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  3. Kittamaru Ashes to ashes, dust to dust. Adieu, Sciforums. Valued Senior Member

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    Okay, talking with my wife (Alerya), she walked me through it:

    The idea is to take the number you are subtracting (subtrahend), and add to it until you reach the number you are subtracting from (the minuend). They do this in such a way as to make it nice, round numbers:

    12+3=15, because counting in 5's is easy
    15+5=20, because counting in 10's is even easier
    20+10=30
    30+2=32

    Then, they take the numbers they added to the subtrahend, and add them together - in this case, 3+5+10+2, and the resulting answer is 20.

    How this is easier than regular old subtraction... I don't know. I also don't know if or how this will work with things such as fractions/decimals, exponents, variables, etc...
     
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  5. zgmc Registered Senior Member

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    WOw. That is just ridiculous. this is going to confuse the crap out of alot of kids. I would not have guessed at how they were doing that. They have taken a simple two step subtraction problem, and somehow made it 4 steps. I wonder how many teachers are refusing to teach that way?
     
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  7. danshawen Valued Senior Member

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    If it were not for the bogus and arbitrary denominations, this method would be analogous to giving back change without needing a calculator or help from making all correct entries in a cash register.

    I agree, it's obtuse. This math teacher needs a better lesson plan.
     
  8. danshawen Valued Senior Member

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    duplicate post -- deleted
     
    Last edited: Jul 23, 2014
  9. Kittamaru Ashes to ashes, dust to dust. Adieu, Sciforums. Valued Senior Member

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    Unfortunately, this isn't a specific teacher... Common Core is a broad-reaching federal system for trying to "standardize" grades K-12

    Which is just stupid, because last I checked, there's no such thing as a "standardized child"...
     
  10. Dinosaur Rational Skeptic Valued Senior Member

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    Is this merely a bad example of a plausible concept?

    If not, it looks so ridiculous that I wonder how it got accepted by anyone.
     
  11. GeoffP Caput gerat lupinum Valued Senior Member

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    It's an absurd concept, developed by fools in the hope that it would be more intuitive and less 'abstract', I believe. It turns a one-step process into that involving several steps, each of dubious intuitiveness and fraught with error if the narrative is, for a moment, forgotten. It is another failure of the system. It should be abolished and its creators sternly reprimanded.

    Edit: In fact, I wrote our local district superintendent and informed him that in no way would we be supporting the efforts of the district to implement this farce.

    Specifically, I told him that we would be teaching the ordinary method at home, in order to repair the damage that Common Core sought to inflict on our children, and that in reviewing homework for return, we would ignore all proscribed CC methods and return such homework using the ordinary system, as above in Figure 1. We would not support or impart any such CC nonsense at home, but rather that we would openly ridicule it to our children, and teach them the standard points of such ridicule for repetition in their classes. In class, moreover, they were to ignore this system completely, and produce all results using the ordinary system. I did sympathise also with his unfortunate place, stuck delivering an unworkable system to the defenseless. Lastly, I invited him to share my letter with his superiors.

    None so far has dared to contradict me, and none will.
     
  12. zgmc Registered Senior Member

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    I hope they do away with that rubbish before I have to use a similar tactic. I fear that it will stick around, because most parents don't oat enough attention to what is going on.
     
  13. Michael 歌舞伎 Valued Senior Member

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    I hear Pearson may be making a killing off this farce. They're (apparently) also preparing some of the State's certification and licencing tests. Thus, if you want 'your' child* to pass these State tests, they'll need to understand that "New" system.

    * actually, your child is now 'the communities' child - for the 'social good' of course.


    I'd look for a K-8 or K-12 Chartered Montessori.
     
  14. Aqueous Id flat Earth skeptic Valued Senior Member

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    The example given looks more like propaganda than anything. If the purpose here is to decide for or against Common Core on its merits, I would begin here:

    http://www.nea.org/home/56614.htm

    So far so good.

    Looks to me like the example given has been misinterpreted. I am not familiar with the particulars of Common Core since I haven't taught in the schools for a very long time. So I would first need to know what the lesson plan for the cited example says. It looks contrived, to lure the unsuspecting person into a sense of outrage by deliberately misrepresenting what the goals for this math unit really are.

    The conventional way to subtract is to apply the addition/subtraction tables, which have to be memorized. I suspect that's still part of Common Core, while this is looks like an approach to introduce techniques like estimation. Since I often apply a similar technique to figure some kinds of problems in my head, the use of this to help kids think on their feet is fine.

    I doubt seriously that Common Core applies this particular method in substitution for the conventional method. I think that's gloss added by the Right Wing, who haven't been able to take a hint from the judges who have told them to get their noses out of the classroom (evolution). Besides, the Right Wing anti-academics crowd can't be trusted to publish anything more than propaganda, so I'm smelling something rotten in Denmark before even coming up with a typical lesson plan.

    Just as I don't tell my plumber how to sweat pipe, and I don't call out the bolt torque schedule to my car mechanic, I don't tend to assume that NEA is unqualified to make teaching decisions, esp. since I know they are working from decades of research compiled by specialists who I couldn't touch with a ten foot pole.

    I'll see if I can prove that the example given is propaganda or not; but I suspect it is.

    Edit:

    Ok I actually found where this example came from.

    http://video.roanoke.com/WebExtra-Common-Core--Math-25708558?playlistId=10245#.U9Cfmvk7uSo

    She says several times this is not done in substitution of the conventional method, but as "another way to look at the same problem". When asked why, the presenter explains "so the student can understand quantitatively why they're doing what they're doing . . . so the students can have different kinds of ways of looking at problems . . . as they progress through school, they pick up different ways to solve math problems, and it makes them better math thinkers later on.

    So it's not replacing conventional subtraction.

    If you read more on Common Core, you'll realize that using a method like this, which can be done in the kid's head, is typical of the ways kids in, say China, are brought up. And as we all know, those kids are much better prepared in math and basic literacy than many American children are. And the reasons for that are that we never standardized our schools to establish and meet core skill competencies, the way those countries have done. So this is a fix. (Not this example, but the adoption of the standards).

    I could just as well have covered a unit in two digit addition and subtraction, and then spent a day presenting a way to estimate the same problems in their heads, without paper or pencil. For example, I might have suggested that they round the two numbers, subtract (easy) then correct for the rounding (a little harder, but by now they have an estimate to work with). Like I say, I often do something similar when figuring numbers in my head.
     
    Last edited: Jul 24, 2014
  15. zgmc Registered Senior Member

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    Thanks for the great post Aqueous. I was finding it hard to believe that they weren't still teaching the proper way.
     
  16. leopold Valued Senior Member

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    well then, let's invent one.
    how's this:
    "brats with halos"
     
  17. GeoffP Caput gerat lupinum Valued Senior Member

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    AI - it isn't. My kids have brought home very similar problems and been told to use very similar methodologies to solve them. CC is literally that counter-intuitive and malign. The right wing needs to be doubted on issues of evolution, but they're not lying when they point out the absurdity of CC maths.
     
  18. Kittamaru Ashes to ashes, dust to dust. Adieu, Sciforums. Valued Senior Member

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    Likewise, my niece is being taught this garbage in school... the more things change with the education system, the more my wife and I think that, when we have kids, we will simply homeschool them...
     
  19. Aqueous Id flat Earth skeptic Valued Senior Member

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    It seems to me that this particular method is equivalent to using an abacus. While it may seem cumbersome, I do believe that children who learn this method will learn to calculate in their heads and develop better analytical skills. What you see them doing is mentally moving the beads. The abacus was popular when I was a kid and I believe today that it helped me to figure numbers in my head which gave me confidence and thereby to consistently do well in math. Keep in mind that the goals of Common Core include achieving standards of excellence found in the curricula of countries like China. It is conceivable that this particular method was even borrowed from Asia. I don't think that's a bad thing. In any case you may feel some resentment not normally seen in places like Asia where parents probably tend to defer to the judgment of their educators. And it may be is that a person such as myself is not afraid of common core because I have a slightly deeper understanding of educational objectives and the work that goes into developing a curriculum from my own academic studies in education. One thing I'm sure of is that in my own parents were never critical of my teachers or of the curriculum. You have to be careful about the effects on your youngsters if you convey to them that the system is broken.
     
  20. danshawen Valued Senior Member

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    Glenn Beck (the former rodeo clown) is intensifying his campaign against common core. This puts me in the uncomfortable position of needing to advocate it. I will advocate no cause that issues from the mouth of GB.

    Well, Common Core is less punitive to teachers and school systems than NCLB for a start. I'd rather have states decide the curricula that will be taught than the Fed. Also, if states own the copyrights on assessment materials, it will be more economical. I think Common Core allows them to do that. Even Kansas and Louisiana have signed. Alaska, Nebraska, Texas, and Virginia are among the few holdouts.

    How about less focus on punishing teachers and school systems, and greater focus on the needs of students? Why not revoke, roll back or otherwise limit copyright law for assessment materials?
     
  21. sideshowbob Sorry, wrong number. Valued Senior Member

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    That was the impression I got when I first read the example. It seems pretty intuitive to me but then mathematics has never been my strongest point.

    (And I found the knee-jerk reactions by most members to be quite amusing.)
     
  22. iceaura Valued Senior Member

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    First: nothing in any post of mine is to be interpreted as a defense of further obtuse bureaucratic inroads into math classrooms: New Math, New New Math, Common Core procedure mandating, or anything else like that, OK?

    The example appears to be of the de-contextualized residue of a perfectly good, even desirable and worthy, and intuitively sound approach to helping a kid understand subtraction. As someone pointed out above, it is exactly the way clerks were once taught to make change at sales and bank counters - the loss of that practical skill is iirc a common complaint among the bemoaners of modern schooling?

    The objection I would have is if the specific numbers chosen to add up - the 3, then the 5, etc - were somehow mandatory; if there were "right" and "wrong" steps other than the final answer, and a kid who chose to add a 10 and a 10 or an 8 and 10 and a 2 were marked "wrong". That is not presented. I fear that is the case, but that is not the example here.

    Obviously one cannot simply transfer the procedure there to fractions, negative numbers, etc - but neither can one so extend the allegedly "one step" procedure it is compared with (which in fact would involve multiple steps of "carrying the ten" and similar obscure and confusing stuff with even a small change in the specific numbers).

    That approach looks perfectly good (so far) in the hands of a reasonable teacher not oppressed by some bureaucratic requirement (that they add by fives, say). It even strikes me as a good idea, not only for practical mental arithmetic and estimation in common situations but also in setting the child up for long division later.

    No approach can survive a bad teacher. If you are hiring from the bottom of the academic barrel, evaluating performance via piles of standardized test results, paying low wages, and dumping forty student classrooms on your math teacher there, Common Core is not your problem (or your solution).

    Furthermore: The difficulty so many posters here seem to have figuring out what was going on there strikes me as an indication that maybe the "Old Way" needed some tweaking, eh?
     
  23. Kittamaru Ashes to ashes, dust to dust. Adieu, Sciforums. Valued Senior Member

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    I still don't see the reason to change math so drastically... and to be blunt, doing complex mathematical equations in your head will ALWAYS be a bad idea. If you are working on an engineering project to build a bridge that will carry a train loaded with people across a river, you can be damn sure that if you went up to the foreman with the plans and said 'Don't worry, I did the math in my head' you'd end up fired... no, you would write it all out, and double or even triple check it, just to be sure.

    There's a REASON we have tools such as calculators - for when things MUST be right.

    Save the mental math for trying to figure out how much of a tip to leave, or how when estimating your cost per mile for your cars fuel economy...
     

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