Tell me about your math...

[hsing1]

How would you read:

 

4

x3

 

 

The reason I ask is that I would read it "4 times 3" where our math curriculum says it should be "3 times 4". (And would be considered 3 sets of 4 each).

[skaterbabs]

IMO:

 

Four times three is equal to (or the same as) three times four. Either way you get twelve. I'm not sure it really matters unless you have a child who just doesn't understand the concept of HOW multiplication works.

[MamaT]

I don't know if it matters either way, but I would read it bottom to top.

[Capt_Uhura]

Programs do it different ways. As others have pointed out, if you understand commutative property and what multiplication means, it doesn't matter in the end. However, in RS for example, it may ask DC to give an array 5x3 which is 3 rows of 5 and not 5 rows of 3. RS interprets 5x3 as 5 taken 3 times. It is the reverse in Singapore Math. 5x3 would be 5 sets of 3 so you'd get a different array. Yes they are the same if you turn the page 90. I can't remember exactly but I believe RS said it does 5x3 as 5 taken 3 times b/c it transfers later to coordinates where you're reading x,y ie it's the horizontal axis first and then the vertical direction so 5x3 is 5 rows (horizontal) taken 3 times (vertical). I think that's what it said but I could be dreaming. Anyone feel free to correct me.

 

I thought of it as 5 sets of 3 so it took some retraining for me to do it the RS way but the RS way seems very intuitive to my boys. I don't think it matters as long as you're consistent.

[Peggy in Va]

:iagree:

 

I would read it as 4 times 3. I can see what they're saying - if you stress the "times" and maybe pause after the 4 - like 4 (pause) times 3.

 

When my dss were that age I just told them that the "x" meant groups of. So I would read that as 4 groups of 3.

 

Bottom lilne - I don't know that it matters unless you're arranging rows of chairs or something. However, someone more "mathy" might have a different opinion.

 

Good luck

 

Peggy

[sixpence1978]

Our math teaches it that way. I just told my DS that it really didn't matter (we went over the commutative property) but that I always read it from top down.

 

I think like a PP said, this comes up more in math programs that teach a lot more conceptually so they are trying to emphasize that. But I just crossed those "tips" off our worksheets.

[abbeyej]

I would read top to bottom because if they were doing subtraction or division, it *would* matter. Obviously, we also discuss which operations are commutative and which are not (and why), but in reading problems like that, I would absolutely read top-to-bottom because that's a habit I want in-grained.

[Targhee]

The real question is how you read this

4

- 3

 

Because 4 minus three is different than three minus 4. I read it 4 minus three (likewise I read it 4 times 3).

[MSherman]

:iagree:

 

I would read it 4 times 3.

[ELaurie]

4 x 3, but if I had to guess, I would say that it is taught this way to prepare your dc for multiple digit multiplication later, which is read from bottom to top.

 

For example, when multiplying 236 x 21, I would begin by saying 1 x 6, then 1 x 3 (or, to be accurate, 1 x 30) and so on.

[mcconnellboys]

It really doesn't matter as multiplication is commutative and so you can read it either way: four sets of 3 or three sets of 4. They both equal the same thing.

[CatMomof3]

I would read it 4 three times.

But that is just me.

 

Alison

[dragons in the flower bed]

How would you read:

 

4

x3

 

 

The reason I ask is that I would read it "4 times 3" where our math curriculum says it should be "3 times 4". (And would be considered 3 sets of 4 each).

 

I would read it as three times four, but a year ago I would not have.

 

Turns out for some kids it's a pain to relearn to read multiplication problems from the bottom right hand corner up & outwards when they get to multiple digit multiplication. My eight-year-old is one of those kids. (My eleven-year-old wasn't and we did it the other way, as I had learned it in school.)

[joannqn]

I would read it as 4 times 3 but explain that it means four counted 3 times.

[Spy Car]

The real question is how you read this

4

- 3

 

Because 4 minus three is different than three minus 4. I read it 4 minus three (likewise I read it 4 times 3).

 

On the other hand, we could look the the equation as the sum of (4) and (-3), and that would be "communicative" as it equals the sum of (-3) and (4).

 

Bill

[Reya]

How would you read:

 

4

x3

 

 

The reason I ask is that I would read it "4 times 3" where our math curriculum says it should be "3 times 4". (And would be considered 3 sets of 4 each).

 

You are correct, the curriculum wrong. That is bizarre. May I ask which curriculum?

[dirty ethel rackham]

On the other hand, we could look the the equation as the sum of (4) and (-3), and that would be "communicative" as it equals the sum of (-3) and (4).

 

Bill

 

There you go, Bill ... Getting all Mathy on us now. (BTW, I agree.)

[Susie in MS]

I read that in the R&S 3rd grade text last night and had to go :confused:

 

I showed it to my 21 yo dd and her reply was, "Ooookay. Whatever."

 

It doesn't matter.

[ELaurie]

You are correct, the curriculum wrong. That is bizarre. May I ask which curriculum?

 

My take on this is that her math program simply uses a different approach.

 

While I would most likely read it 4 times 3 as well, some math programs teach students to read from the bottom up (3 x 4) in preparation for multiple digit multiplication later on.

 

For example, when multiplying 224 x 23, one would begin with 3 x 4 and proceed from there.

[SnowWhite]

Right... I noticed that in our curriculum as well and realized EXACTLY why they do it. For the same reason that children must ALWAYS add starting on the right side, then moving left, even before they rename/regroup/carry. Teach the proper order and direction of thought in the beginning to avoid confusion later.