Is this a "common core" problem?

[mjr]

But the problem more is this: even beyond whether it makes sense or not, this is a matter of following directions. It would be like saying a teacher should accept, without penalty, a paper done in MLA when the directions said to put it in APA. Just because they're both citation methods doesn't mean you get to ignore the directions.

The directions, according to the question on the worksheet, are:

"Use the repeated addition strategy to solve 5 x 3."

[Kheldarson]

The directions, according to the question on the worksheet, are:

"Use the repeated addition strategy to solve 5 x 3."

Right. But we don’t know what that means in the context of the class. If they were taught that the repeated addition strategy meant reading the first number as the number of groups and the second as the number you're adding, then doing the reverse means you're not following instructions.

[mjr]

If they were taught that the repeated addition strategy meant reading the first number as the number of groups and the second as the number you're adding, then doing the reverse means you're not following instructions.

If that's the case, it would seem like there's a flaw there. Which, I'm sure you'd agree, is a problem. Either with how CC is supposed to be taught, or with the teacher's curriculum, or with the teacher.

[Gravekeeper]

If that's the case, it would seem like there's a flaw there. Which, I'm sure you'd agree, is a problem. Either with how CC is supposed to be taught, or with the teacher's curriculum, or with the teacher.

Again, reading 5 x 3 as five groups of three *is* the lesson. You guys can argue back and forth till your blue in the face about how 5 x 3 is read and it doesn't matter. The context of the lesson as part of CC is to read 5 x 3 and five groups of three. And that's that.

Also, again, the basis of teaching this alternative method is because it helps build critical thinking towards more advanced mathematics in the later high school courses. This method is not meant to replace or supplant the standard reading. Its meant to augment the student's understanding and thus problem solving abilities for later down the road in math.

TL;DR this entire fiasco is because one parent doesn't understand or pay attention to their child's education and assumed they were right instead of asking the teacher.

[mjr]

Again, reading 5 x 3 as five groups of three *is* the lesson. You guys can argue back and forth till your blue in the face about how 5 x 3 is read and it doesn't matter. The context of the lesson as part of CC is to read 5 x 3 and five groups of three. And that's that.

Then from a common sense standpoint, the lesson is WRONG.

[Kheldarson]

If that's the case, it would seem like there's a flaw there. Which, I'm sure you'd agree, is a problem. Either with how CC is supposed to be taught, or with the teacher's curriculum, or with the teacher.

I don't actually. Because, again, multiplication is communicative. So learning it one way or another doesn't matter. And, frankly, learning different grouping methods and patterns is downright helpful for upper level math.

[Gravekeeper]

That seems like an awfully confusing way to teach it, given the 5 x 3 aspect of the question.

Confusing how? If I taught you to read 5 x 3 as five groups of three then quizzed you on how to read 5 x 3 how I taught you; Would you be confused? I certainly hope not. Your entire argument is getting ridiculous. It doesn't matter how you read it out of context, you are not the student and you are not privy to the lesson being taught. None of us are.

So this whole argument is pretty pointless. Without knowing the lesson, the teacher, the student or the parent all we're left with is a little bit of internet outrage bait for people to get riled up over.

We may as well be arguing over whether or not a dress is white or blue.

But how about one more vid, just for good measure?

What exactly are you trying to prove? That there are stupid teachers out there? That school boards suck? That textbook manufacturers are idiots? We already knew all that. So where are you going with this?

[Gravekeeper]

And, frankly, learning different grouping methods and patterns is downright helpful for upper level math.

Precisely. Multiplication is commutative in the abstract. However, understanding things like grouping patterns and what not help with upper level math. Which is the point with CC.

In the abstract, 5 x 3 or 3 x 5 are the same and basic math would read 5 x 3 as 5 times 3. 3 fives. However, here's a difference between the "common sense" understanding of 5 x 3 = 15 and the grouping of five groups of three.

Its the difference between:

"What is 5 x 3?"

and

"You have five bags of three oranges, how many oranges do you have?"

Which is the kind of thing the CC standards are trying to teach.

[mjr]

I don't actually. Because, again, multiplication is communicative. So learning it one way or another doesn't matter. And, frankly, learning different grouping methods and patterns is downright helpful for upper level math.

I think you mean commutative...

But anyway, I think it DOES matter. Because 5 x 3 is NOT

3 + 3 + 3+ 3 + 3.

No matter how you slice it. It's 5 + 5 + 5.

Why? Because 5 x 3 is five, three times, as I've said numerous times.

5 x 3 is NOT "five groups of three". It is, in fact, "three groups of five".

Saying that 5 x 3 is "five groups of three" is backward.

[KabeRinnaul]

Kinda sounds like this is "New Math" all over again, where it's perfectly reasonable logic, works out fine once you learn it, and emphasizes understanding methodology, but everyone hates it cause it's different.

https://www.youtube.com/watch?v=UIKGV2cTgqA

[mjr]

Confusing how? If I taught you to read 5 x 3 as five groups of three then quizzed you on how to read 5 x 3 how I taught you; Would you be confused?

Irrelevant to the discussion. The fact of the matter is that 5 x 3 is NOT "five groups of three". It is, in fact, "three groups of five".

you are not the student and you are not privy to the lesson being taught. None of us are.

While true, the mathematician (with a PhD, I might add) who was originally supposed to be a part of developing the math part of the CC said he couldn't endorse it once they got done with it. I think that's mentioned in one of the videos.

Without knowing the lesson, the teacher, the student or the parent all we're left with is a little bit of internet outrage bait for people to get riled up over.

You're partially right. I'm simply going by the actual wording of the question as it appears on the worksheet. 5 + 5 + 5 IS the correct answer. THREE GROUPS OF FIVE, not Five groups of three.

So where are you going with this?

Does it really matter? The bottom line is students AND parents are struggling with this.

[Aragarthiel]

mjr, just because it's not the way YOU learned how to multiply, that doesn't mean it's confusing. I learned the "5 groups of 3" method in the second grade. It never confused me, or anyone in my class. It is not necessarily WRONG, just a different method of teaching multiplication. What is wrong is that students aren't being taught that 3 x 5 works just as well as 5 x 3, they're being taught that one is correct and the other isn't.

It's clear that the people here were all taught different methods for the same problem. That doesn't make any particular method wrong. I just finished a college-level algebra class and when I was trying to solve for x, it really didn't matter if I multiplied 17 by 4.1 or if I multiplied 4.1 by 17. They both come out to the same answer. I don't use "groups of" anymore, since it's faster to do it in my head or on paper than to add it all up.

[Kheldarson]

I think you mean commutative...

Probably.

But anyway, I think it DOES matter. Because 5 x 3 is NOT

3 + 3 + 3+ 3 + 3.

No matter how you slice it. It's 5 + 5 + 5.

Why? Because 5 x 3 is five, three times, as I've said numerous times.

5 x 3 is NOT "five groups of three". It is, in fact, "three groups of five".

Saying that 5 x 3 is "five groups of three" is backward.

And that’s your way of saying it. And that may be how you learned it. But it doesn’t make five groups of three any less wrong. Nor does it make your way more right.

And which way is more right doesn't matter when the teacher has, whether from personal preference, standards, or just the mood they were in, declared a preferred way of having it written out.

[mjr]

where it's perfectly reasonable logic

Here's some "perfectly reasonable logic" when it comes to CC...

Simple subtraction. Subtract 12 from 32.

Most of us would simply do the following:

32
-12
----
20

Not CC...Nooooooo....

Do you know what THEY do??

12 + 3 = 15
15 + 5 = 20
20 + 10 = 30
30 + 2 = 32

3 + 5 = 8 + 10 = 18 + 2 = 20.

So, how exactly is that better? Or even a good method, at ALL?

https://www.youtube.com/watch?v=Ldyl_uYrojs

Or maybe this:

Subtract 270 from 530.

Again, most of us would just do this:

530
-270
-----
260

Which is not, supposedly, "Common Core Friendly", even though, again, the answer is correct.

The "common core" way is to add 30 to both numbers first, ending up with 560 and 300, and THEN subtract.

https://www.youtube.com/watch?v=1x2ZyXWHeMw

As the lady said, paraphrasing, "You can get the correct answer, but it's not right, because you didn't use some ridiculous, convoluted Common Core way that only makes sense to the five people who wrote it."

Do they even teach the concept of "borrowing" anymore?

I say "good luck" to these kids when they have to keep a checkbook register.

[mjr]

But it doesn’t make five groups of three any less wrong.

Yes, it does make "five groups of three" wrong. Because it is.

And which way is more right doesn't matter when the teacher has, whether from personal preference, standards, or just the mood they were in, declared a preferred way of having it written out.

So now we're counting off for "preferred" ways of writing things out?

So even if 5 + 5 + 5 is correct (and it is), if the teacher prefers it to be 3 + 3 + 3 + 3 + 3, then, by your statement, that is the "correct" answer?

I don't think it works that way.