The dysfunction of Common Core...

[alexpgp]

I get the distinct impression that if I were being taught math these days, I'd be doing much worse than I did back in the bad old days (reckoned as "before 'New Math'" but somewhat after 'making impressions in wax tablets').

Consider the following problem, answer, and (apparently) teacher's comment, from a post at IJReview:


Me, I can see the kid's point. On the one hand, that may be so because I never could see the point of explaining to my teacher why addition was commutative, while subtraction was not. It just seemed intuitive to me.

On the other, it may just be that—in my opinion—asking a kid to "make 10 when adding 8 + 5" is a little like asking someone to "determine how much soap to use when making potato salad." (The answer, by the way, is "enough to wash your hands thoroughly before handling food." Isn't that, like, obvious?)

But what really, really kills me is the educator's comment. Read it closely.

What's the result when you "take 2 from 5 and add it to 8"?

Dunno about you, kimosabe, but I get 11, not 10.

Why are we asking kids questions to which teachers apparently have trouble explaining the answers?

Given that the teacher's answer is—let's face it—wrong, I'd say the kid won this one.

Cheers...

P.S. It occurs to me that, if you follow the teacher's attempt to explain how to get the answer, there is an alternative answer—involving subtracting 3 from 8 and adding the result to 5—that is equally valid. Come to think of it, I can also add 8 + 5 to get 13 right off the bat and then subtract 3. Is this abundance of answers a good thing? Maybe later on, but in grade school? I think that had I been exposed to this kind of drivel, I would have very likely shoved it all to the side at the first opportunity and become a math-hater for the rest of my life.

Comments

[apollo14.livejournal.com]

It's just so wrong :(

[bandicoot.livejournal.com]

I think what the teacher meant and expressed so obtusely is that you take 2 from 5 and hold that 2 in your hand (as opposed to subtracting 2 from 8) and then add that 2 to 8, making 10. The form of both the question and the answer (or comment) is highly incompetent for someone who is supposed to be teaching concepts.

Also, apparently they also badly flunk on the ability to teach penmanship, unless the kid is in second grade.

[alexpgp.livejournal.com]

Yes, I see what you mean: "take 2 from 5 and add that same 2 to 8." I interpreted "it" to mean the result of taking 2 from 5.

Gee, I guess, for this problem, the correctness of the answer really does depend on what the meaning of "it" is.

So I suppose I should upgrade the teacher's explanation from "wrong" to merely "grossly ambiguous."

Cheers...

[halfshellvenus.livejournal.com]

I frankly cannot believe what is coming out of the Common Core objective for math.

This is not the first thing I've seen where the child's answer is considered wrong... because they actually understand math.

The method the teacher explains here (apart from being wrong) is a worthless exercise in voodoo. Can you imagine, in language arts:

Spell "apple."
Answer: "apple" is spelled applicable, where you take out the letters i through the second l.

Gah.

[kehlen-crow.livejournal.com]

Pretty much. It's like that anecdote, 'Dad, how do I write the number 8? ' - 'Easy, son: take the infinity sign and rotate it by Pi/2'

[alexpgp.livejournal.com]

That reminds me of the joke about the famous Australian sheep-counter who had the uncanny ability to determine exactly how many sheep there were in a flock, and to do so consistently.

When asked how he did it, the follow responded, "Nothin' easier, mate! I just count the number of legs, and divide by four!"

Cheers...

[alexpgp.livejournal.com]

For some reason, your example brought to mind an old magician acquaintance of mine who, upon being asked to spell his name (which happened to be "Fred"), would reply, without the slightest hesitation and with a completely deadpan face, as follows:

"F-S-R-E-D. The 'S' is silent."

Cheers...

[halfshellvenus.livejournal.com]

YES. The difference is, the general public knows that's ridiculous.

The people creating the common core apparently do not. :(

[alexpgp.livejournal.com]

Excellent distinction.

Cheers...

[kehlen-crow.livejournal.com]

Technically, your answer to the potato salad question is wrong for some families where all vegetables and fruit are washed with soap (yikes). Just shows that trick questions are wrong.

[alexpgp.livejournal.com]

LOL! Nice observation!

There was a book I read in college (The Tyranny of Testing, by Banesh Hoffman) that took a really hard look at testing and, among other topics, just how difficult it is to come up with "good" questions.

I remember how, among other issues, the book discussed questions of the form "Which is the 'odd one out' among...?" for example: cricket, soccer, billiards, and hockey"—where any of the choices would work, depending on what criterion you focus on. This has the unfortunate consequence of forcing the person taking the test to try to read the mind of the person writing the test.

Cheers...

[houseboatonstyx.livejournal.com]

Aside from the teacher’s own blunder, here is what my near-Dr-Seuss-era mind suggests for a legitimate grade school problem.

Give some values for x and y so that:

8+5-x-y=10

or

8+x+5+y Hint: Negative numbers are allowed here and below.

Or for more complexity:

(8+x)+(5+y)=10


And if the kid comes back with:

Set z = -3
x+y=z
What are the possible ranges of x and y such that:

(8+z)+(5+z)=10

… fire the teacher and hire the kid. Well, fire the teacher anyway. And whoever wrote that test question.

And your 'it' question could be useful if we ask:

Insert parentheses such that:

5-3+8+x = ... oh well, too many versions of that!

[alexpgp.livejournal.com]

I'm not sure I follow your approach entirely, but I get a feel for what you're trying to get at.

There are numerous ways of skinning this particular cat, which is bad enough. What's potentially much worse is that The System™ likely promotes one and only one approach as being Right™.

Cheers...

[houseboatonstyx.livejournal.com]

And as you point out, even the same Approach(tm) (even without the ambiguous 'is') could have multiple right answers. I bet only that one was in the teacher's notes.

[houseboatonstyx.livejournal.com]

Must say I loved New Math 1962, partly because my college teacher was Margaret Rutherford playing Miss Marple. ;-)