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Trying to teach dd long division


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With ds I broke it down...

424/4 (for instance)

First, let's divide the biggest group into as many even groups we can. How many hundreds do we have? (4) Okay, how many groups of four can we get from that? (....1) Right! Now, let's divide the tens up. How many tens do we have? (uh, 2) How many groups of four can we get from that? (uh.... none?) Right! Now, we still have 2 tens to divide, let's add in our ones and see if we can divide it. We know we have no whole groups of ten, so we'll put a zero in the tens place. How many tens and ones do we have? (uh..... 2 and 4) How many groups of four can we get from 24? (uh............................... 6?) Very good! So we have six groups of four from the ones.

 

For some reason this isn't translating too well into type, but a few problems like this and he "got" it. I just had to show him that we divide the biggest numbers first, so we could drop down those numbers when there wasn't enough to divide or we had a few left over.

 

When we're done, I go back and show him the multiplication problem that's the equivalent and if possible write out the repeat addition problem. That seemed to help too.

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One dd really struggled with long division in third grade. Some curriculums have it in there, I know ABeka does, but others don't. Personally, I don't think many dc, even very bright ones, are developmentally ready for long division in 3rd grade. This was a big reason why we switched from ABeka to CLE. When she reached it in CLE, she was ready.

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Do you have a set of Base 10 blocks? It really helped my dd in 4th grade when I used those. I didn't think she would need them, but she just wasn't 'getting it'. Once we started using the Base 10 blocks, it all clicked for her.

 

I'm now using them for my younger ds who is in 4th grade. It hasn't become automatic for him yet (ie doing it with pencil and paper), but he can do it with the blocks.

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My older learned division in 2nd grade, and it turns out that, like me, he really prefers short division. It helps for your child to have a very solid grasp on place value--using base 10 blocks can really help cement long division for many children. I think Singapore does this very well, but my guess is Math Mammoth probably explains it similarly.

 

For long division, I would check out the Khan Academy videos--they're wonderful. I am linking you directly to his long division and here's a

on youtube.
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I had to do short division instead with my two younger girls. It makes much more sense and is a lot easier to do as long as you know your math facts.

 

link to written explanation:

http://www.themathpage.com/arith/divide-whole-numbers.htm

http://www.wikihow.com/Do-Short-Division

 

link to video explanation:

-- I think this is the easiest one to follow.

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Well I only know one way to do division, and it's not the way Saxon teaches. (I confess, we gave up trying to understand Saxon's explanation and we do it Mom's way :gnorsi: )

 

Which is:

 

856 divided by 4

 

4 goes into 8 twice - put down the 2 above the 8

4 goes into 5 once - put down 1 above the 5 and carry 1 to the 6 to make it 16

4 goes into 16 4 times - put down 4 above the 6

 

Answer 214

 

I guess that's short division?

 

It still works - however big your number.

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Do you have any suggestions??? I have tried the division family (dad,mom,sister,brother==divide,multiply,subtract,bring down)

 

Nothing is working. She just is not understanding. :banghead: :banghead: :banghead: I am BEGGING for suggestions! :001_huh:

 

Is it lack of understanding or that she doesn't recall the steps?

With 2 of mine, so far, I sat down and did each step with them, one problem a day, every day, til they remembered it on their own.

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Do you have any suggestions??? I have tried the division family (dad,mom,sister,brother==divide,multiply,subtract,bring down)

 

Nothing is working. She just is not understanding. :banghead: :banghead: :banghead: I am BEGGING for suggestions! :001_huh:

 

This is going to have a lot of ....in it to keep the spacing, but this is the way that clicks for my kids:

 

.......02,407 R1..

23|62,583

......-0...........(0x23)

........62..........(carry down the 2, I draw an arrow from the 2 above to the 2 below)

......-52.........(2x23)

.........105........(carry down the 5, I draw an arrow from the 5 above to the 5 below)

.......-104.......(4x23)

...............18......(carry down the 8, drawing an arrow from the 8 above to the 8 below)

..............-0.......(0x23)

...............183.....(carry down the 3, drawing an arrow from the 3 above to the 3 below)

.............-182.....(7x23)

....................1

 

Then I write a sample problem we have walked through like this on a 3x5 card and allow them to use it as a reference as much as need.

 

I also spend time with manuplatives and talk about how tedious it would be to start with the ones and break things into groups, how then we have to go back and re-adjust the ones, so they can physically see the need to start with the bigger place value and work to the smaller number.

 

I also think it is important to NOT make logical leaps with the ones that are 0. They just don't get why they can make those leaps till later, so don't make them at first, don't allow them to confuse the issue.

 

Last I think it is important to write the multiplication out to the side for a while so it isn't so intangible. Otherwise it seems like you are pulling numbers out of thin air.

 

Heather

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Is it lack of understanding or that she doesn't recall the steps?

With 2 of mine, so far, I sat down and did each step with them, one problem a day, every day, til they remembered it on their own.

 

Yes, its the steps. She gets them mixed up. I have sat down with her and did the steps over and over and over again (6 1/2 pages worth) I have written them down and had her tell me and everything.

 

Give up. It will probably work in a month, without you doing anything. :)

 

 

I am getting there. Its in her Singapore Intensive Practice book so Im about to give her a little bit then restart.

 

 

 

I am first going to check out some of the other suggestions I was given.. thanks ladies. If she doesnt get it today we are putting it away for a while and continuing with her Horizons :001_smile:

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<sniped>I have sat down with her and did the steps over and over and over again (6 1/2 pages worth)<sniped>

 

FWIW, maybe consider shortening the sessions and spreading the study sessions out over a longer period of time. Think of it like putting butter on toast, an even thin layer tastes better than a single clump in the middle:D

Edited by Ray
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We just tackled this in our house and I hope this will encourage you that you're on the right track.

 

DD8 had the steps (same ones you mentioned in your OP) written at the top of each page - D-M-S-B and she drew arrows to show which number to bring down. I would say it took 2 months of doing this over and over and over (and over) again until it finally clicked.

 

No magic, no brilliant explanation of division - it was the repetition and her maturity over a few months. I now see this is how she learns math. It took almost 4 months of doing subtraction with borrowing for her to finally get it. So now I know we need to keep working at it and I need to be much more patient with this child.

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