Teaching Long Division - any tricks?

[fourcatmom]

My 4th grader is struggling with long division to the point of tears. Ick here a trick to this? We are using TT and we have gone over it but it's not sticking. HELP!

[Lady Marmalade]

Patience. :tongue_smilie:

 

I've been very, very slowly going over long division with my DS. We've been using a white board and different colored markers so that we can clearly identify where numbers go, what number comes next, etc. I also decided to have him draw an arrow everytime he bring a number down, to remind him to do it, and not accidentally repeat a number.

 

It took a good week of doing the basics before I didn't have to walk him through step by step every time. Now he can confidently divide into a three digit number, but I'm already dreading having a larger divisor.

[Ohmomjacquie]

I

I remember being taught thisacronymand it helped me remember the steps

Mom=multiply

Dad=divide

Sister=subtract

Brother=borrow

[kclopez]

Yes, we totally hit a wall with long division. He is dyslexic and the multi steps just were too much. These are some things I've done:

we use Dirty Monkeys Smell bad. (Divide, multiply, subtract, bring down). He uses charts and calculator to do the muliplication and subtraction to take out these mental transitions for now. I used manipulatives to illustrate single digit into multiple digit. Finally, for two digit into multidigit - he has really connected with double division

http://www.doubledivision.org/side-by-side.html

It is not something I would have used with my other children but it really works with him.

Hope something here helps.

k

[thowell]

We used tricks too. We wrote Does Mcdonald's Sell Burgers at the top of every page. Also I took a problem written in extra large type. Color coded each step with a different color marker and then wrote out a key for the colored steps on the worksheet. dd uses this everyday. It helped here remember what to do next.

[nmoira]

Patience, squared paper, use a divisor of 10, frequent reinforcement (just a question or two a day).

[Hunter]

There was a thread about this not the long ago. Someone suggested making your own worksheets and dividing really long numbers by 2. It takes the math out if it and teaches them the rhythm of long division until its routine. I used excel and made a grid to keep his lines neat. I'm on my phone; otherwise I'd link it to you.

 

It was me. This WORKS.

 

If the child is totally phobic, print a copy of a board game, that allows you to supply your own questions. That way the student can watch YOU do some of the 2s problems, and can hope to be able to skip their problem if they get lucky.

 

Big LONG problems, only by two. Chant as you solve them, so you FEEL the rhythm.

[Abbeygurl4]

Graph paper helped to keep all the numbers lined up.

[foxbridgeacademy]

We used graph paper and wrote Dad, Mom, Sister, Brother.... then I sat with him for every single lesson until he remembered it. Also I think it's important that they understand the concept. Division is breaking the larger number into equal parts. This helped him a lot when it came to fractions too.

[jetted4]

What I found made sense for my ds9 was this:

 

Example: 92 divided by 4.

1) explain that the goal of the division is to figure out how many sets of 4 that you can split your dividend (92) into.

 

2) Multiplying by 10s is pretty easy, so start by asking if they can pull 10 sets of 4 out of 92. Yes, they can. OK, what about 20 sets of 4? Yes, you can pull 20 sets of 4 out of 92. What about 30? No, you cannot pull 30 sets out, so when determining the 10s, you can only go up to 20 before having to stop.

 

3) 20 sets of 4 is 80, so you subtract 80 and you are left with 12. That's easy to figure out if you know the multiplication tables: you can pull 3 more sets of 4 out.

 

4) Add the 20 sets of 4 and the 3 sets of 4 together and you pulled 23 sets of 4 out of 92.

 

3

20

4 [92

 

5) Do a number of these until they understand what is going on. Then eventually you can show them that they just need to write the '2' (tens) above the '9' (tens) and write the 3 next to it (since 2 tens plus 3 is 23).

 

We did these with 2 digit dividends for a while then expanded into 3 digit dividends.

3-digit example: 774 divided by 2... can you pull 100 sets of 2 out of 774? Yes. Can you pull 200 sets out? Yes. 300 sets? Yes, but not 400. Take 300 sets of 2 out (600), that leaves you with 174. Then ask about 10 sets of 2, 20 sets of 2....(you can skip over some of them if it is obvious that it'll be a high number) on up to 80 sets of 2. Take out 80 sets of 2 (160) and you're left with 14, which is 7 sets of 2. 300 sets plus 80 sets plus 7 sets equals 387 sets of 2)

 

Once he was solid in understanding why this was working we switched over to the short-cut rules of just dividing into the 1st digit (but still remembering the place value of what we were dividing by), subtracting, then dropping the next digit down and so on (the standard method that is taught). Since he understood the process behind it, the regular short-cut was pretty straight-forward when we got to it.

[Laughingmommy]

We've been doing this no-tears way. DD9 is a perfectionist and fearful about new things.

 

Our current method:

 

Say, you're dividing 300 by 5, we say, "what's a good number to try?" So, maybe we try 10, then we get 5*10=50, we put the 10 on top, subtract the 50 from the big number, and keep going. "How about we try 10 again?" Then we subtract another 50 from the total. Slowly, we chisel away at the number in a comfortable way until the number is all gone. Then we add up all the numbers on top to get the answer.

 

This way works really well for my daughter. She keeps gaining more confidence with the method and concept. It helps her do a lot of what she's good at (adding, subtracting, and multiplication with numbers she feels safe with) which helps her explore what she fears (multiplication with numbers she doesn't feel safe with and division) in a really gentle way.

 

Good luck! Just don't YOU get to the point of tears! It's just long division. It'll be okay. Your child will figure it out for sure... sooner or later! ;)

[fourcatmom]

Those are all really great suggestions. I appreciate it. Yes, I would agree that I needed to find my patience. I knew there was a trick that I had read about on her but couldn't remember so I ended up asking my older dd to come over and show her on the white board. The younger one was at the table crying. My older dd and I started doing it on the white board with different colors and chanting with the DMSB R concept. Our cat's name is Rocky, so she sort of took to this quickly. I think in the end, she was understanding more but we will continue to work at it. I think the idea of doing a really long number divided by 2 is a great idea. And, she does need to still work on her multiplication tables.

 

Thanks again! :001_smile:

[SilverMoon]

We acted out the first several problems with blocks. Cuisenaire rods or a big pile of 2x2 Legos are perfect. Make a pile of blocks as big a the dividend. Divide just the hundreds by 4 (or whatever your divisor is), then you have to take out what you already divided to see what's still left that hasn't been divided. Pull the tens down to go with it, lather, rinse, repeat.

 

I don't introduce a mnemonic as a shortcut until they've demonstrated understanding a few days in a row.

[momofsbandeg]

Graph paper helped to keep all the numbers lined up.

 

This is my favorite hint. The little squares keep all the numbers in tidy rows. :)

 

I'd try graph paper if you haven't before.

[mamakelly]

A friend suggested the

 

Daddy= divide

Mommy= multiply

Sister= subtract

Brother= bring down

Rover= repeat or remainder

 

trick to us, and it worked like a charm.