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Why '5+5+5=15' is wrong under the Common Core
Business Insider ^ | October 25, 2015 | Jacob Shamsian

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 ...


TOPICS: Education
KEYWORDS: addition; arth; commoncore; education; math; mathematics; repeatedaddition
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To: Lets Roll NOW
Have you seen kids try to figure out the change you should get back?

Picture this. The total due is $7.35. I'll hand over $13.00. The clerk will tell me it's only 7.35 and take the ten. I pocket a fistful of ones.

61 posted on 10/25/2015 5:22:54 PM PDT by FoxInSocks ("Hope is not a course of action." -- M. O'Neal, USMC)
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To: W.

Like hell they are. They are SUCCEEDING. There is no try. And they are REALLY good at it.


62 posted on 10/25/2015 5:23:22 PM PDT by Norm Lenhart (Embrace "Existential Cage Theory")
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To: Ingtar

Everybody knows that mulitiplication tables are racist.

Get out of here with your white-centric math and stuff.


63 posted on 10/25/2015 5:24:43 PM PDT by bakeneko
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To: editor-surveyor

I know what it is. It’s something people mentally unfit for creative writing at a high level do to keep their little pea brains occupied...

(Said the guy that failed algebra ;)


64 posted on 10/25/2015 5:28:45 PM PDT by Norm Lenhart (Embrace "Existential Cage Theory")
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To: grundle

RE: “it’s the wrong answer”.

Big Brother: “Winston Smith, tell me how many fingers I’m showing now!”

Winston Smith: “three, four, or two, it’s anything you say they are - anything. Please, I beg you, stop torturing me!”

George Orwell’s 1984 (a socialist’s guide for governing)


65 posted on 10/25/2015 5:34:36 PM PDT by MarchonDC09122009 (When is our next march on DC? When have we had enough?)
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To: grundle

The nuns taught us our multiplication tables in first grade and how to add, subtract, multiply, divide and take square roots by third grade.

Everything the feral government touches it destroys.


66 posted on 10/25/2015 5:35:02 PM PDT by E. Pluribus Unum (Is the pope Catholic?)
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To: gop4lyf

“I teach 4th grade Math. This year at our Open House night, I had to prove to several parents that we don’t use Common Core lessons or curriculum.”

Fantastic! Good for you and your school system for not using the Ebonics of education, and good for the parents demanding that you don’t.


67 posted on 10/25/2015 5:37:09 PM PDT by CodeToad (Stupid kills, but not nearly enough!)
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To: editor-surveyor
Calculus for the following y=f(x) is generally referred to a single variable calculus. There is even an MIT open courseware course called
68 posted on 10/25/2015 5:40:21 PM PDT by ronnietherocket3 (Mary is understood by the heart, not study of scripture.)
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To: grundle

Wreck the system.

Say 5+5+5.

Never give up.

If the common core edu-robots fail everyone based on common cores warped ideas , then common core will collapse.

Wreck the system.


69 posted on 10/25/2015 5:42:18 PM PDT by WildHighlander57 ((WildHighlander57, returning after lurking since 2000)
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To: Ingtar

BINGO!
That’s what I told our kid’s idiot third grade teacher, when she was teaching bullsh1t Mimosa “new” math in the mid-nineties.
Fixed that cap with homemade multiplication flash cards in one night. The kid memorized the tables up to 12 x 12.
His fifth grade scout friends semi-boasted that they still had to use their fingers or hash marks on paper.

Our kid became a successful EE.
His fifth grade slacker friends went into government studies..

The adle-brained educational system, and crappy parented kids guarantees our continued downfall.

RE: “5 X 3 = 15 and should not need to be factored out if they were still memorizing their tables.”


70 posted on 10/25/2015 5:42:35 PM PDT by MarchonDC09122009 (When is our next march on DC? When have we had enough?)
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To: tet68
Some can’t do that so it’s only fair that none can do that.

You have it the wrong way around.

It is actually easy to memorize the table and everyone can do it. That is why they do not do it. The goal is not to educate but to prevent education by making everything very confusing. That way only a very few will come out of public education with any sort of idea of what is going on.

These methods are not used in the private schools of the elite.

71 posted on 10/25/2015 5:42:50 PM PDT by Harmless Teddy Bear (Proud Infidel, Gun Nut, Religious Fanatic and Freedom Fiend)
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To: ronnietherocket3; editor-surveyor
Evidently, my post did not finish. It should have been: Calculus for the following y=f(x) is generally referred to a single variable calculus. There is even an MIT open courseware course called Single Variable Calculus.
72 posted on 10/25/2015 5:44:05 PM PDT by ronnietherocket3 (Mary is understood by the heart, not study of scripture.)
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To: Leaning Right

Do it anyway.

After hours extra credit :D


73 posted on 10/25/2015 5:45:01 PM PDT by WildHighlander57 ((WildHighlander57, returning after lurking since 2000)
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To: grundle
This is dumb. For one who counts out 5 x 3 quickly on their fingers ("skip counting"), they'll use 5, the first number, and count on three fingers 5,10,15. If they switch it. they're more likely to make a mistake.

For students who are average or struggle a bit with math, quickly counting out the numbers, using the sense of touch, helps them learn their times tables faster.

Common Core is insane.

74 posted on 10/25/2015 5:50:15 PM PDT by grania
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To: metmom

re: Common Core. Piaget must be rolling over in his grave


75 posted on 10/25/2015 5:55:33 PM PDT by grania
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To: Paladin2

actually it’s a rule....as in commutative


76 posted on 10/25/2015 5:57:43 PM PDT by Nifster (I see puppy dogs in the clouds)
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To: rigelkentaurus

true that


77 posted on 10/25/2015 5:58:13 PM PDT by Nifster (I see puppy dogs in the clouds)
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To: WildHighlander57
Do it anyway. After hours extra credit :D

I like the way you think. Because it certainly can't be done (legally) in the classroom.

Here's an example. Our physics curriculum handbook (actually it's a big binder), sets out in detail what I must teach every day. No variations permitted! There are no lessons on torque. So I must not teach it! But torque is a key concept in physics.

So I sneak it in wherever I can. Fortunately, most supervisors who observe me know nothing about physics. So I haven't been accused (yet) of "infidelity to the curriculum".

Yes, that's the term they actually use. And it's a firing offense. Crazy.

78 posted on 10/25/2015 6:01:56 PM PDT by Leaning Right (Why am I holding this lantern? I am looking for the next Reagan.)
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To: grundle

Zero is my hero.


79 posted on 10/25/2015 6:05:06 PM PDT by P.O.E. (Pray for America)
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To: grundle

I know for a fact several Elementary school teachers tell their students up from that their parents will be shocked at what is being taught and just won’t understand it. They do things the ‘old way’, but *we* do math the new and improved way.

Message being your parents are old school; old fogies who just aren’t ‘with it. Disregard your parents’ ignorance and learn it our way.

Enough of them do it where it’s got to come from a central source. Whether it’s the official CC line, I don’t know.


80 posted on 10/25/2015 6:05:20 PM PDT by MichaelCorleone (Jesus Christ is not a religion. He's the Truth.)
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