5 reasons not to share that Common Core worksheet on Facebook

You are browsing Facebook on a Sunday evening. Someone has shared a baffling piece of math homework that was sent home with their child. Accompanying commentary bemoans the current state and future trajectory of mathematics teaching and learning, and lays blame for this at the feet of the Common Core State Standards.

You are baffled by the worksheet too. You are about to click the Share button.

But here are five reasons that’s a bad idea.

1. Credentials are not a trump card.

Almost invariably, the parent who shares the worksheet cites a degree as a credential for the critique. “I have a Bachelor of Science in electronics engineering,” wrote the parent in the recent “Letter to Jack”.

frustrated.parent

The math you need to know to be an electronics engineer is different from the math you need to know to be a math teacher. I am quite certain that electronics engineers use math that I have not studied, and similarly I use mathematical ideas that they have not studied.

When my teacher friends watch the following video of my son Griffin, they tend to see that a number line would be the right thing to draw to capture his thinking, and they tend to know what is coming when he goes to solve the problem on paper. They tend to describe my son’s work as demonstrating competence or proficiency with subtraction, but suffering mechanical errors when solving with paper and pencil.

Non-teachers who view this video are less likely to see a connection to the number line, and they tend to consider Griffin’s knowledge of subtraction to be weak. 

The difference is that teachers have a different kind of mathematical knowledge from electrical engineers. Not necessarily more or less knowledge—different knowledge. This is because different mathematical knowledge is required to do their job.

Deborah Ball refers to this different knowledge as mathematical knowledge for teaching. It is what mathematics teachers know who are more successful in their work. This knowledge includes common errors with standard algorithms, as well as their sources [start at about 2:30 in this video]. It includes common correct, alternative ways of performing and showing computations.

Moral of the story: You may not want to look to an electrical engineer as your primary resource for the current state of math teaching.

2. It is probably misinterpreted.

Homework time can be stressful. This is not new to Common Core. 

Parents are trying simultaneously to be helpers and enforcers. When a child does not understand what appears to be something simple, tempers can flare

We parents are not at our most rational at these times, and this may prevent us from fully understanding the goal of the task. 

When Frustrated Parent wrote to Jack, he committed two important errors of misinterpretation: (1) He assumed that Jack’s method was being taught as a preferred algorithm for subtraction, and (2) He assumed that something unfamiliar to him must be complicated.

These are totally understandable. I do not hold Frustrated Parent in contempt for his frustration.

I am simply asking the rest of us to resist sharing without asking critical questions.

The strategy shown on this particular worksheet is counting back

This is how many people count change: You gave me $20.00 for a $3.18 item, so you get $17 minus $0.18 in change…that’s $16.90 minus $0.08…$16.82. 

The number line Jack drew captures this thinking. 

The number line could have been improved by (1) arrows on the arches, and (2) smaller jumps to suggest that Jack is counting by a small number (as it is, the relative sizes of the pictured jumps on the number line suggest Jack is counting by 10s or 20s to the left of 127—as Frustrated Parent notes in a later Facebook post).

fp.better.num.line

This worksheet was not about getting students to use the number line as an algorithm. It was about having students try to understand the thinking of someone else.

This may have been a bad worksheet—but not for the reasons cited when people share it on Facebook.

[For the record, in this case Jack’s error was forgetting to subtract the 10 in 316. He counted back three hundred, then six ones. The result is that his answer (indicated on the left-hand end of the number line) is too big by 10. He gets 121. The correct answer is 111.]

3. It is probably not “Common Core”.

There is nothing in the Common Core State Standards that requires students to use number lines to perform multi-digit subtraction. In fact, standard 4.NBT.B.4  requires students to “Fluently add and subtract multi-digit whole numbers using the standard algorithm”.

The standard algorithm, of course, is what the frustrated parent suggests that Jack use.

4. Anecdotal evidence is not research data.

While parents who share these worksheets in frustration will make claims such as the old way worked for me, the research evidence is quite strong that the old ways did not work.

Changes being made to American mathematics teaching are (1) very slow to take root, and (2) based on years of American and international research on student learning. 

5. Teachers need our support, not our scorn.

The frustration and anger of a parent who is struggling to help their struggling child is completely understandable. Any parent who claims they have never been frustrated at homework time is living in (a) a fantasy world, (b) denial, or (c) both.

But when we widely share the product of others’ frustration online, we amplify the anger. Ultimately, classroom teachers are the targets of this anger, as they are the public face of the education system. As a group, teachers work very hard with limited resources. They are called upon to equalize the inequities our society creates, and to offer not just equal educational opportunities, but equal educational outcomes to all children.

Now—more than ever—teachers need our support, not our scorn.

What to do instead

If you are Frustrated Parent, you can write a level-headed note to the teacher. It might look something like this:

Dear Ms. Crabapple,

I worked with my child on this problem tonight. Neither of us could figure out what is going on with the number line. You can see the work we did together, but we did not know how to write an explanation to Jack. We are confused. Please help.

Sincerely,

Frustrated Parent

If you run across the work of another Frustrated Parent online, please consider asking someone about it before sharing it as evidence of the decline of American mathematics education.  Some possibilities:

Ask a teacher friend. You probably have at least one on Facebook. 

Ask on Twitter. There are many eager-to-help math teachers who follow the hashtags #mtbos and #mathchat—sincere questions asked on those hashtags will get sincere answers and offers of help.

Ask on a website. The Mathematics Educators stack exchange is a new resource for people to ask and answer questions related to teaching and learning mathematics. Anyone is welcome to ask a question, anyone can answer, and everyone votes on the quality of the answers so that you can easily find the best ones.

Note: Things got far beyond my ability to curate in the comments, so I needed to turn comments off. I would be more than happy to take up the dialogue on Twitter or through a pingback to your blog. You can also contact me if you wish to discuss further—Hit the About/Contact link at the top of the page.

Second note: I will curate and organize the major threads of the comment discussion in the coming days. In the meantime, I have sequestered the existing comments as the discussion threatened to overwhelm the point of the initial post. I have not deleted them.

A quick Fox TURD for you

A Truly Unfortunate Representation of Data (T.U.R.D.) from Fox News.

Posted without comment.

turd

Thanks to David Radcliffe for passing it along on Twitter.

The latest “Common Core” worksheet

You have seen this on Facebook.

Original (Click to enlarge)

Ugh what a mess.

Please share the annotated version widely.

I’ll say what I have to say (comments closed) and move on. If you wish to discuss further, hit me up on Twitter or pingback to the blog. Want to talk in private? Click the About/Contact link up top.

Also, Justin Aion—middle school teacher extraordinaire—wrote up his views on the matter. You can read them over in his house.

Here goes…

The intended answer

Dear Jack,

You only subtracted 306 from 427, not 316. You need to subtract another 10 to get the correct answer of 111.

Sincerely,

Helpful student

The purpose of this task

I cannot say whether this was the right task for this child at this time because I do not know the child, the teacher or the classroom.

I can say the following:

  • Analyzing errors is a useful way to encourage metacognition, which means thinking about your thinking. This is an important part of training our minds.
  • The number line here is a representation of a certain kind of thinking—counting back. The number line is not the algorithm. The number line records Jack’s thinking. He counted back from 427 by hundreds. Then he counted back by ones. He skipped the tens. We can see this error because he recorded his thinking with a number line.
  • Coincidentally, the calculation in question requires no regrouping (borrowing) in the standard algorithm, so the problem appears deceptively simple in its simplified version.
  • This task is intended to help students connect the steps of the standard (simplified) algorithm with reasoning that is based on the values of the numbers involved. Why count back by three big jumps? Because you are subtracting 300-something. Why count back by six small jumps? Because you are subtracting something-something-6. Wait! What happened to the 1 in the tens place? Oops. Jack forgot it. That’s his mistake.

So what?

The Common Core State Standards do require students to use number lines more than is common practice in many present elementary curricula. When well executed, these number lines provide support for kids to express their mental math strategies.

No one is advocating that children need to draw a number line to compute multi-digit subtraction problems that they can quickly execute in other ways.

The Common Core State Standards dictate teaching the standard algorithms for all four arithmetic operations.

But the “Frustrated Parent” who signed that letter, and the many people with whom that letter resonated, seem not to understand that they themselves think the way Jack is trying to in this task.

Here is the test of that.

A task

What is 1001 minus 2?

You had better not be getting out paper and pencil for this. As an adult “with extensive study in differential equations,” you had better be able to do it as quickly as my 9-year old.

He knows with certainty that 1001 minus 2 is 999. But he does not know how to get the algorithm to make that happen.

If I have to choose one of those two—(1) Know the correct answer with certainty based on the values of the numbers involved, and (2) Get the correct answer using a particular algorithm, but needing paper and pencil to solve this and similar problems—I choose (1) every time.

But we don’t have to choose. We need to work on both.

That’s not Common Core.

That’s common sense.

[Comments closed]

Brief thoughts on being ready for calculus

A smart friend (whose permission I have not asked) read an article of mine that will be published in Mathematics Teaching in the Middle School sometime soon. The article is based on my NCTM talk last spring, titled “They’ll Need It for Calculus”.

This friend asked by email:

For clarification: are you arguing that the sorts of problems that you point to will help students better understand calculus, or that these sorts of problems will help students do better in their calculus classes?

I was pretty sure that you were making the first argument, but not the second.

My reply, which I stand by, is this:

That these two things are different from each other is a pretty damning critique of the whole affair, is it not?

You know what will help them do well in their calculus classes? Memorizing about 20 of these:

 

The Fundamental Theorem of Calculus

I have taught Griffin (9 years old) the Fundamental Theorem of Calculus.

That is…

\frac{d}{dx} \int_{a}^{x} f(t)dt=f(x)

Details and discussion coming soon.

In the meantime, see Kristin’s related post.

Full disclosure. Griffin was paid a sum of $0.25 for his performance.

The hierarchy of hexagons, continued

Max asks in the comments of the original hierarchy of hexagons post (and, if you are new to this, see also the follow up post)…

In defining Bobs, Stacys, and the like, did you run into situations where your definition admitted shapes the students didn’t actually want. For example, once you defined a Stacey as a hexagon with three congruent acute angles, did you draw some other Stacys and have students blurt out “wait, that’s not a Stacy — that’s not what I meant!” If not, how did you privilege the *definition* over some sense of “I know a Stacy when I see one.” Is it because their definitions were based on some property they liked about one example, rather than trying to say what was the defining quality of some *group* of hexagons?

Yes, yes, yes.

This instructional sequence is all about moving through the van Hiele levels.

An important learning goal for these lessons is for students to separate what it looks like from its mathematical properties. That means we need to talk about this very issue.

Early in the process, a central challenge is identifying precisely the property the student had in mind. This requires a use of language that can be unfamiliar and strange. Does “has a right angle” include rectangles, which have several right angles? Or did you mean “has exactly one right angle”? That sort of work comes first.

Then we look for other shapes that have this property. If those early-discovered shapes violate the spirit of the original intent, the student may object and will be invited to revise. If she wants to add another property, then I will usually suggest that this is a second class of shapes, and that the one she was really after is the combination of these two classes.

So your shape is special because it has all sides the same length AND it has at least one right angle. Let’s do this…let’s call hexagons with all sides the same length equilateral and let’s give a name to hexagons with at least one right angle…Who has a name for us?

A “sally”? Good. From now on, a sally is a hexagon with at least one right angle.

Now this shape is both equilateral and a sally. Let’s give this special category of shape a new name.

Et cetera.

That’s OK on day 1. Our goal on day 1 of the lesson sequence is to have a set of between five and eight named classes of shapes that have interesting interrelationships.

I need to be the judge of when we have enough, and whether they are of sufficiently interesting variety (I have screwed this up before). I reserve the right to add in some properties that I know will be interesting. For example, I make sure concave and equilateral make it into the mix somehow—either by student introduction or by my own.

After day 1, we need to move away from what things look like. We will be operating only on the properties as we have defined them. If we accidentally left ambiguities, we can plug those holes as clarifications. But these definitions cannot otherwise change. It is important to notice that shapes with very different appearances can share important properties.

It is important to notice that mathematical properties of shapes behave differently from the look of a shape.

For example, this semester we defined a class of hexagons this way.

windmill is a hexagon with three acute angles and three angles greater than 180°.

The iconic windmill is this one.

Screen shot 2014-03-14 at 3.04.24 PM

Much later, as we were in the process of trying to decide whether a windmill can be a utah (a utah is defined as a hexagon with two sets of three parallel sides), we happened upon this most un-windmillish object.

Screen shot 2014-03-14 at 3.05.01 PM

In trying to push the limits of windmill-ness, we started to consider shapes that had the right properties but that looked nothing like the original shape.

Addendum

For what it’s worth, we have produced a proof—which some of us can reproduce and others cannot—that a windmill is never a utah. This proof depends on the Dani principle, which states that when two sides of a polygon are parallel and separated by a single side, then the two angles formed sum to 180°. This happens twice in a utah, which accounts for 4 angles less than 180°, leaving (at most) two possible angles to be greater that 180°, and thus a utah is not a windmill.

It should further be noted that the Dani principle needs amending to admit the possibility of angles that sum to 360° (when one of them is greater than 180°) or 540° (when they are both greater than 180°). And it should be yet further noted that standards for proof are socially negotiated in all areas of mathematics, and that we had become quite confident that these cases would not come up with a utah, thus the weak version of the Dani principle was good enough for our work.

Finally, if you have made it this far, you may be interested in the speculative origins of the hierarchy of hexagons. It has been a long road.

NCTM

I will be presenting the hierarchy of hexagons at NCTM in New Orleans. Friday morning at 8:00 a.m. See you there?

That Chicago PD video

Is this how people learn?

This has made the rounds on the Internet, and it has angered lots of folks in education. And rightly so. Because there is no learning going on in that video.

But those teachers are being trained to deliver that sort of instruction to students in classrooms. Go ahead and search EDI or whole-brain teaching. You’ll see these very techniques being promoted as good practice.

So, is it how people learn, or is it not?

Tip of the cap to David Wees for reminding me that the parallels are not necessarily obvious.