Posted on 10/25/2015 3:53:05 PM PDT by grundle
Here's a "repeated addition" Common Core problem that's taught in third grade in US schools:
Use the repeated-addition strategy to solve: 5x3
If you answer the question with "5+5+5=15,” you would be wrong.
The correct answer is "3+3+3+3+3.”
Mathematically, both are correct. But under Common Core, you're supposed to read "5x3" as "five groups of three." So "three groups of five" is wrong.
According to Common Core defenders, this method will be useful when students do more advanced math. This way of reading things, for instance, can be used when students learn matrices in multivariable calculus in high school.
But parents aren't happy about it.
(Excerpt) Read more at businessinsider.com ...
You know, I can't actually remember. It's just the weirdness of the whole process that has stuck with me.
just started reading it.
I’m pretty sure that Sergeant Donny Donowitz could explain to the Common Core people EXACTLY why they’re wrong...
Once again, you have the wrong end of the stick.
It is not that "inner-city children cannot memorize" it is that they can.
What they can not do, along with most non-inner-city children, is figure out the mess that is Common Core.
And lacking parents to try to puzzle it out math will remain forever the unknown country. This will leave them neatly trapped in their cast forever having to do what their political masters order to survive.
Democrats are not in any way shape or form trying to help minorities, they are doing their best to lock them into the dependent or servant class.
What's the purpose of the problem? If it's to teach what that × symbol means, then strictly speaking this is correct: 5×3 ("5 times 3") means "3, 5 times," or 3+3+3+3+3. I think it's pedantic, but not necessarily foolish or wrong. Five groups of three is not the same thing as three groups of five, even if both do happen to comprise the same number of units.
I memorized my times tables in third grade. They certainly didn't trust us with big words like "commutative property" until years later.
My son’s teacher last year tried to tell me that, at a private school no less, that I probably didn’t understand math well, which is why we were struggling with the homework.
I said any adult who finished high school should be able to help a fourth grader with math. And as a degreed engineer, and my husband with a masters’ in engineering, if two people who actually use algebra, geometry and calculus for work can’t understand two digit by two digit multiplication, the problem was their teaching method, not the concept.
We taught our son how to do standard multiplication the way people have done it for decades, and he got the right answer. She then counted it wrong for using the wrong method.
I pulled out a calculator and showed her that the answer was right, and counting it wrong for the method every adult in the building learned was petty if not evil.
The parent teacher council has since dumped common core and that teacher.
This year, the public school in our area has ditched most of common core. And the poor public fifth graders who have used it for years need remedial work to learn to add, subtract, multiply and divide at third grade levels.
The differential of one variable with respect to another, the most basic concept of the calculus, demands at least two variables.
In a function such as f(x) = x2, there is only one variable, x. Any function that can be graphed on an x-y plane is a single-variable function. The y isn't a variable; it's an output.
Later.....
You’re a moron.
oh if you mean da gubmint....then I can’t argue that
F(x)=X2 ...... f’=2x
2) Commutative Property of Multiplication.
3) Do these people know the difference between arithmetic and mathematics?
I disagree. There are definitely wrong ways. If you were to say that there are often multiple correct ways in arithmetic and mathematics, I'd agree with you.
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The “slope” is what is sought (1st deriv.) not ‘x’ nor’y.’
Since you already have the equation that represents the function, neither of the variables is an unknown.
It is amazing how many people can’t focus on what they are really doing. Even “common core” may be above their heads.
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>> “ Do these people know the difference between arithmetic and mathematics?” <<
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No, obviously.
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‘X’ is not the variable, it is merely one of two parameters.
The slope is the variable sought.
More coffee help?
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4 / 10 can’t be solved by inspection?
This is why my husband and I - a pair of, as you put it, degreed engineers who do this for a living - are homeschooling our daughter. I get to choose the curriculum. I even picked something that isn't "the traditional way", but rather an Asian-influenced style -- but I made darn sure it made sense to me before we got it!
Forcing you to use a particular method rather than finding the right answer is, like you said, evil.
Can you not get it that f(x) means some function of x. As in say f(x) = x^2 (x squared) and then f'=2x where f' is the notation for denoting the first derivative of f(x) which in this case is x squared. Now just because f(x) can be represented as y (as in y=x^2) does not make that a multivariate differential calculus problem! Find f'(x,y) where f(x,y)=(y^2)(x^2) would be a multivariate differential calculus problem.
I figured you where to dense to simply admit your mistake.
Is that your expert opinion as a qualified professional moronologist? What should I do, doc?
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