As you may know if you follow me on Facebook, I pretty much hate, with a capital H-A-T-E, this “new common core” math being taught. Every day it’s a massive struggle for Chris and me, him with a Masters Degree and myself with a Bachelors, to teach 3rd grade homework to our daughter.

Putting aside that we work for hours past an *already* 8 hour school day, ignoring that we are provided no text books to learn about the material, and sweeping under the rug that they send home homework on things they have yet to even teach yet, we are doing our best.

But we are lost.

**LOST. **

And I am a bit angry to tell you the truth.

Today was just another example of “fuzzy” math.

This is on Charlotte’s homework:

All her problems have to be done this way.

Under what math EVER would 291 be “estimated” or “rounded off” to 200? Am I missing something? And this is the example for her to base all her other math homework on.

I can tell you that if I estimated or rounded off my bills from $291 to $200, I would get a notice of an unpaid bill. I am not sure my mortgage or car payment would agree with that.

And let’s jump to the answer. The estimated sum ’500′ is *considered reasonable* with ’645′?

Is 5 million the same as 6.5 million? Ask an accountant that. Ask a corporation that.

I can’t help but wanting to refuse to teach Charlotte something that I find completely and utterly wrong.

~trisha

Seems like she is asked to provide the actual sum, so it’s not like they’re skimping on that.

I can see the value in estimation to ensure you’re in the ballpark even if you’re not right, but I have to agree that rounding off 291 to 200 is sloppy. At the very least, it should round to 300 and 300. I would actually round to 350 and 300, but I will not fault someone for choosing to round only to the nearest hundred.

This type of teaching has nothing to do with Common Core. This is about your child’s school curriculum choices. Common Core has nothing to do with curriculum. I am a teacher. I can tell you first hand that Common Core is nothing but a list of standards students are required to meet. How the school chooses to teach them is up to each individual school district. I am not necessarily in favor of CC, but I am getting sick and tired of folks who aren’t in education and have not been through the training blaming everything they don’t like or understand about what their child is being taught on CC. If someone at your child’s school is telling you that this is Common Core Math they are either lying or they themselves have not been educated about what Common Core is.

By the way, I just looked up and read the Alabama Common Core State Standards for 3rd grade math and no where does it mention front-end estimation as a standard. I repeat, this math has NOTHING to do with Common Core.

So I’ve spent some more time thinking about this, and I think my position is that on the one hand, the technique is of highly dubious value and there’s an argument that time shouldn’t be spent teaching it, but on the other I maintain that it’s alarming that neither you nor your husband could understand the technique.

First, the technique itself. On three-digit summands it catches errors outside of a range of 200, and where that range is centered relative to the correct value varies based on the second and third digits of the summands. I’ll admit that I no longer have any but the vaguest memory of what it’s like to have a third-grader’s understanding of math (or a sixth-grader’s, for that matter), but my guess is that most errors on these problems are likely to be small relative to 200—forgetting to carry, or double-carrying, or incorrectly performing addition on two single-digit numbers. Since you have to be able to add the leading digits correctly to get the estimate correct, it effectively only works for errors that make the result too large. It looks like it’s really mostly useful when the last two digits of both numbers are relatively large—which admittedly is probably the circumstance in which elementary schoolers would most likely be making mistakes, but since it has so little value the student won’t have a good reason to use it for its own sake, which means it will quickly be forgotten. Unless the entire point of teaching this is to reinforce principles like two two-digit numbers summing to less than 200, I can’t see any point to it.

That said, on to understanding:

“Under what math EVER would 291 be “estimated” or “rounded off” to 200?”

Well, let’s look at what happens when you make different rounding/truncation choices. You seem to want to use the standard unqualified “rounding” rules ( 0, ≥5 –> 10); the third option is to always round up (we’ll ignore other options like round-to-even). Since the given example makes standard rounding and rounding up the same, we’ll instead use 344 and 291.

If you round down, you get an estimate of 500, so you know the answer is between 500 and 700.

If you round up, you get an estimate of 700, so you know the answer is between 700 and 500.

If you round-on-5s, you get an estimate of 600. What’s the answer between? There are ways of recovering the interval, but I’m pretty sure they’re all more difficult than simply adding the original two sums, which entirely defeats the purpose.

So that’s why we don’t want to round-on-5s. As we see, rounding up and down are in one sense equivalent, but keeping in mind that we’re talking about third-graders the fact that rounding down simply involves taking the first digit is pretty compelling. Then the upper bound is calculated with addition instead of subtraction, which I seem to remember as being easier at that age.

The question then is why you two didn’t see this. In the post, you repeatedly conflate the estimate with the result despite the problem clearly saying that the estimate is “to check that each answer is reasonable”. Although my initial reaction was to question your math ability, and I still think that’s part of the issue, I wonder now if the problem isn’t your assumptions going into the worksheet. Given your stated strong negative views on the current math curriculum, I’m thinking that when you encountered something that at first glance seemed counterintuitive or nonsensical you concluded that it was nonsense rather than examining it further to see if your conclusion was justified and maybe running some numbers.

Anyway, I can’t say I know enough about the Common Core to have an opinion on it (I don’t have a dog in the fight, as it were), but it seems to me that by failing to understand the technique being taught you weaken your criticism—instead of a strong argument that time and effort is being wasted on an unenlightening and marginally-useful technique that will probably never be used again and will be promptly forgotten, you have an easily-rebuttable argument that the technique is “fuzzy math” and “completely and utterly wrong”.

Um, Common Core is one Evil indoctrination by Commies, and should be rejected outright! If the idiotic public schools insist on this garbage, take your children OUT of these Marxist day care centers, and teach them at home. Anyone who cannot see through this BS..is either a flaming “progressive” or a complete moron.

Appears in order to explain and defend this assignment example is to have a background in applied logic and congnitive reasoning to get into the mechanics within the methodology. An adventure in descriptive sequence and pathway search.

A fair assumption if you are already grounded in formuli calculus in order to have to provide such a lengthy explanation which would cause a 3rd grader to skip school… forever. As well, not to have to impress anyone with an already college level, masters degree in math.

There is too much suggestion of redundancy, wasted exercise and weak provision of true or even practical, if not useful direction, to simpler problem solving.

Just to get to the truth and final solution.

A problem, of any variety, needs not to be treated with such useless abuse.

Here’s some info on front end estimation. It is an actual math concept to help add large numbers together quickly: http://www.basic-mathematics.com/front-end-estimation.html. That being said the numbers should be rounded up to the nearest hundredth. 400 and 300. Should be added together according to this site. . Fun note: once you have 700 you can then subtract in your head what you added to the two numbers to get the correct summation of the original numbers.

I am as retired teacher. I have seen many so-called education gurus come and go with all their BS on how to teach kids. Most of these idiots have never been in the classroom. Someone in education needs to wake up and tell the powers in charge that we need to go back to the basics.. Memorizing the multiplication tables, learning how to diagram sentences, and learning correct grammar must be put back into schools. The educational BS of No Child Left Behind and Common Core are just more ways that somebody is making big money. We are falling further behind the world in educating our youth because we will not return to the basics. Kids cannot even make change anymore. We are graduating students with no work skills. They cannot be successful in the job market in America. You see more Asians in the top jobs because our kids are not being prepared properly for today’s jobs. We must stand up and stop these worthless education programs before the only jobs our youth will be able to do will be minimum wage employment.

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Well, there’s all sorts of ways to check “reasonable”. One of my rules is that if two odd numbers are multiplied, the answer, whatever it is, has to be odd. Any even answer is unreasonable, in the sense that you ought to know that it has to be wrong.

It isn’t about mathematics. It’s about marxism and destroying western civilisation. The last enemy of marxism on the planet is American freedom.

For a look at Common Core and other problems caused by No Child Left Behind and Race to the Top I suggest parents read Reign of Error – The Hoax of the Privatization Movement and the Danger to America’s Public Schools by Diane Ravitch.

My son is also in 3rd grade and I’m finding the Common Core math infuriating as well. However, the above example seems like a typo. We’re doing the same thing right now in math and it’s never asked us to round a number above 50 downwards. I would ask the teacher about that, if s/he even knows. My son’s teacher admitted to me that the teachers at his school haven’t even received the proper training in Common Core yet! Unreal. So, the next time I get a progress report saying my son has an issue with explaining why/how he got to the answer of the simple math problem, I’m going to throw it in the trash.

That’s why it’s called front end estimation. You just look at the first number and throw out the rest regardless of whether it’s over or under the halfway point. I didn’t know about this either and thought it was a mistake. Nope! I first saw this a couple years ago when my high school aged sister in law was living with us and i was like seriously? I have a bachelor’s, masters and doctorate and couldn’t believe this was how they were teaching math now. My kids weren’t school age yet and this scared me and now my girls are in first grade and I’m already frustrated with the way they are being taught. In first grade!! We do our own math studies at home which go well but I’m afraid i could be confusing them even more.

Can you please send me the publisher of that math assignment? I have a group in CT that has formed in response to CC and we are looking for lots of info.

Thanks!

I cannot tell you the last time my daughter brought home a book…we dont get books in our elementary school. They come home w/ these sheets. This article was written in November I believe so this paper is long turned in.

When I was a young child in the 60′s & 70′s they taught us rounding down and rounding up. It hindered my Math growth all of my life. It took playing Domino’s to help me add faster and get the right answer. I hope don’t cause the problem for them as it did for me.