General Discussion

muriel_volestrangler

(106,214 posts)

27. Never having seen a 'number line' before, I can see the idea behind it ...

Mon May 12, 2014, 06:30 AM

May 2014

... but exactly how wrong was 'Jack'?

It seems to me that if you're going to learn subtraction with a number line, you should, as you do in 'normal' maths, start by subtracting units, not the most significant digit. That way, you'll be able to progress smoothly to doing normal subtraction. The number line is, in effect, allowing you to do subtraction (or addition) before you've memorised "7-5=2", "7-8=9 borrowing 1" etc. Given that Jack's main problem was that he forgot to deal with the tens, it seems like it would have been a good idea to write down the number he was subtracting, and cross off digits as he deals with them. Or at least write the '3', '1' and '6' by his stages (in the order he has decided to do them in).

The problem here is that the parent, to help in this, has to know exactly how the use of the number line was taught. Did they teach the children to write down the number they are subtracting, so that they don't get lost? Did Jack come up with the idea of doing the hundreds first, or did someone teach him that? You can't write a critique of Jack's work without knowing everything he was taught. Are they asking for the error Jack made, or the problems with a way he has been taught?

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A frustrated parent responds on a Common Core assignment. Looks like it's back to the old New Math. [View all] madfloridian May 2014 OP

Parent is right. In real world simplication is valued over complicated. madfloridian May 2014 #1

What's really frightening about this. . . . Tansy_Gold May 2014 #2

On The Courteous Assumption This Is Real, Ma'am, I Would Sympathize With The Parent The Magistrate May 2014 #3

It's real. madfloridian May 2014 #8

I Bow To Your Expertise, Ma'am The Magistrate May 2014 #9

They're trying to disconnect algorithms from concepts. joshcryer May 2014 #119

Not only is the page a rightwing screed, but... TreasonousBastard May 2014 #4

Explain your reference to "rightwing screed". madfloridian May 2014 #7

Read the comments about how it's all a liberal conspiracy... TreasonousBastard May 2014 #10

I think the "hotshot engineer" was referring to process mostly. madfloridian May 2014 #17

Where do you get the idea I approve of it? I thought... TreasonousBastard May 2014 #21

Well that is a RW Facebook meme nadinbrzezinski May 2014 #11

Okay, let's have one curriculum thru the whole country. madfloridian May 2014 #16

I don't think it is necessarily a bad thing to have Skidmore May 2014 #34

Do you realize that testing companies will set that curriculum in large part? madfloridian May 2014 #41

Is that the only way it can be done? Skidmore May 2014 #47

I agree, but that is the way it is being done. madfloridian May 2014 #49

I hate to point this out nadinbrzezinski May 2014 #64

The "left" is equally strong in opposition to increased testing. madfloridian May 2014 #33

agreed; I detest the Common Core and am glad our crazy NC GOP is trying to eliminate it zazen May 2014 #55

Look up Sweeden nadinbrzezinski May 2014 #66

Testing IS the problem...it is excessive. Fails both students and teachers. madfloridian May 2014 #68

Testing *is implementation.* nadinbrzezinski May 2014 #72

It also uses the hashtag #tcot, which I find is "top conservatives on twitter" muriel_volestrangler May 2014 #26

Both left and right are strong in opposition to common core, and usually to Arne's "reforms". madfloridian May 2014 #29

that's not the error hollysmom May 2014 #22

Frustrated Parent, realize the Real World is...DUMB! alp227 May 2014 #5

You know what is amazing nadinbrzezinski May 2014 #6

ah, the celebration of willful, determined ignorance and stupidity. unblock May 2014 #12

That is a large part of it nadinbrzezinski May 2014 #14

I consider your last paragraph insulting to parents who really care about their children. madfloridian May 2014 #18

that paragraph was in the context of the op, which unblock May 2014 #52

Anybody that doesn't understand the geometric interpretation of subtraction mathematic May 2014 #13

I think you're the first person I've run into who actually recognizes both what New Math was Ms. Toad May 2014 #15

"This is just the latest in history's long line of teachers corrupting the youth" Really? madfloridian May 2014 #31

Have a technician look at your sarcasm meter. Lizzie Poppet May 2014 #54

No, YOUR post has that theme mathematic May 2014 #56

Seriously???? Maybe this will help..... msanthrope May 2014 #115

Do you believe that teachers have any roody May 2014 #37

A number line can be much more intuitive than simply stating 427-316 = 111 Chathamization May 2014 #70

The number line is confusing to me but I've never had a teacher explain how to use it. Gormy Cuss May 2014 #87

Hah! Don't blame the old new math. I took that as a kid and it was nothing like this. pnwmom May 2014 #19

What does common core have to do with this assignment? Egnever May 2014 #20

Nothing jberryhill May 2014 #51

Why do those people believe the math and Common Core are liberal? Enthusiast May 2014 #23

Becaue the Koch Bros have told them so. baldguy May 2014 #24

most of the comments i read barbtries May 2014 #25

It's Arne Duncan's policy. madfloridian May 2014 #30

And with that sentence you've said it all. TBF May 2014 #32

I've been struggling to understand this as well deutsey May 2014 #35

That last about Louis C K is quite true. Both left and right opposed. madfloridian May 2014 #40

letting Dems pass hardcore GOP/corpo policies lets them be blamed on "libs" (which are MisterP May 2014 #90

thanks for the response. barbtries May 2014 #112

As much as she loves to blame Arne Duncan nadinbrzezinski May 2014 #78

You are right. Arne Duncan is implementing Bush's policies. madfloridian May 2014 #81

Perhaps I don't remember correctly nadinbrzezinski May 2014 #82

I just agreed with you that Democrats are implementing Bush policies. madfloridian May 2014 #85

Has it occurred to you that this is not a party thing nadinbrzezinski May 2014 #89

A trip down memory lane, Nadin.... msanthrope May 2014 #117

Never having seen a 'number line' before, I can see the idea behind it ... muriel_volestrangler May 2014 #27

This was apparently practice for the test. madfloridian May 2014 #28

So I looked for some resources on how to use a number line for subtraction muriel_volestrangler May 2014 #38

Part of the point is that it doesn't matter which end you start from. Warren Stupidity May 2014 #100

Teaching conceptual math is not a bad thing. MineralMan May 2014 #36

The most important thing a strugging student can have is one on one personal instruction Fumesucker May 2014 #43

Absolutely. MineralMan May 2014 #46

Yes, different approaches are needed. madfloridian May 2014 #69

Well, based on the information in the OP, MineralMan May 2014 #75

I took shop in HS and learned a lot from it Fumesucker May 2014 #122

Is this real? This makes no sense. chrisa May 2014 #39

Some of the responses to this thread seem to be seeking confirmation that one, the CC is based Jefferson23 May 2014 #42

Good observation. Is it wrong or right per se, not whether left or right. madfloridian May 2014 #44

The public can and has been misled about CC but that seems to be falling apart..thankfully. Jefferson23 May 2014 #45

Bzzzz: nothing to do with Common Core; myth dispelled in Atlantic frazzled May 2014 #48

Actually under Arne education is not locally controlled. madfloridian May 2014 #50

Your response has nothing to do with the issue frazzled May 2014 #59

Her response does have a great deal to do with the issue, and your OP is far less than accurate: Jefferson23 May 2014 #62

See my other response to you. madfloridian May 2014 #65

I believe frazzled May 2014 #74

Article you posted said education has always been locally controlled. madfloridian May 2014 #63

It doesn't say that at all frazzled May 2014 #76

In the quote you posted: "Education has always been locally controlled" muriel_volestrangler May 2014 #77

Read the second half of the sentence frazzled May 2014 #86

Are you aware of what the conjunction 'and' means? muriel_volestrangler May 2014 #88

I don't know where you are getting all that stuff I did not say. madfloridian May 2014 #79

Why is the second step 127 minus 60 ??? DetlefK May 2014 #53

Good question. madfloridian May 2014 #58

where do you see that? mike_c May 2014 #93

+1. This approach is all about emphasizing place value. winter is coming May 2014 #96

Then, where is the mistake in the exercise? DetlefK May 2014 #118

ah-- it should have been... mike_c May 2014 #123

Hey mad, here's an interesting article in the weekly rag dealing with the testing at a local school. hobbit709 May 2014 #57

Common Core is being used by the big corporations to take billions of dollars of local tax dollars greatlaurel May 2014 #60

My first programming professor used to say, "Simplify, simplify, simplify." CrispyQ May 2014 #61

Yes, we often taught the number line even in early grades. But this one is confusing... madfloridian May 2014 #67

Some basic understanding of the foundations of CC that should be seen as problematic Jefferson23 May 2014 #71

Post removed Post removed May 2014 #73

Wow! "It shows a lack of qualification to act as an educator" Wow. I fooled everyone for 33 years. madfloridian May 2014 #80

You are really hitting a deep nerve when the attacks on you get so nasty. greatlaurel May 2014 #83

.... madfloridian May 2014 #84

You are a true fighter for truth and justice, as are most teachers. greatlaurel May 2014 #94

That one came this close for me to hit the alert button nadinbrzezinski May 2014 #91

+1. My alert and I was pleased to see a unanimous hide. n/t Jefferson23 May 2014 #97

an alternative perspective.... mike_c May 2014 #92

Hi Mike greatlaurel May 2014 #95

Here is a news flash nadinbrzezinski May 2014 #99

That's the problem. No one is asking teachers for solutions. madfloridian May 2014 #102

And.... nadinbrzezinski May 2014 #104

Ravitch has the big guns after her. madfloridian May 2014 #106

Again... and... nadinbrzezinski May 2014 #107

If I could I would. madfloridian May 2014 #108

When you do, let me know nadinbrzezinski May 2014 #109

No, Diane Ravitch does not have the big guns after her. She's a former Bush employee who msanthrope May 2014 #116

You're a good mom. joshcryer May 2014 #120

oh I completely agree with your broader comment about high stakes testing, etc.... mike_c May 2014 #113

Nice post. madfloridian May 2014 #114

a numberline is a fundamental concept in math. Warren Stupidity May 2014 #98

I know. I taught it. I enjoyed it, my class enjoyed it. I am not RW, I am not anti-intellectual. madfloridian May 2014 #101

The test question is fine. You have conflated it with other issues and fallen for Warren Stupidity May 2014 #103

Really? I have "fallen for rightwing anti-intellectual glorifying idiocy bullshit" Wow. madfloridian May 2014 #105

And yet, for integer subtraction like this, it doesn't really help muriel_volestrangler May 2014 #110

Indeed it is, you and I normally agree quite a lot Fumesucker May 2014 #121

Someone is suffering from engineer know-it-all syndrome Taitertots May 2014 #111