Math question(elementary) from a parent

I hope you guys do not mind me picking your brain. Recently DD(10-in 4th grade) has been having a hard time in math. Her teacher has been teaching her the "break apart" method to try and help her with multi digit multiplication(like 736x47=)
What do you ladies know about this method? I am sooo NOT good in math and this method seems like more work and seems confusing to me. It seems like there is more places to make simple math error, etc. I can't even help her when she does it that way(because I do not get it )
Tonight, we sat for an hour with me trying to teach her the traditional way. I feel like she is going to have to know the traditional way at some point anyway.
Am I helping her? Is the break away, a good method?

Re: Math question(elementary) from a parent

I like to keep it together and teach this solving it the traditional way.

What I would do to help her is take out some colored pencils and circle each combination that she has to multiply.

For example:
746
x 4
Have her circle 6 and 4 in blue, 4 and 4 in red and 7 and 4 in green.

If your working with a 2 digit number, repeat this again. Remind her that the digit she is now multiplying is in the tens place, so she needs to "hold it's spot" by putting a 0 in the ones place.

It may be hard if it's written small, so you might want to start using a large piece of paper or wipe board until she gets the hang of it.

Re: Math question(elementary) from a parent

I agree with the above.

Also, I recommend doing any multi digit multiplication on a piece of graph paper. It really helps organize the math and helps them keep digits lined up.

I think the break away method is good for some kids and really establishes good number sense. However, it isn't best for all kids. So if your DD isn't getting it that way, definitely try using a different method. No methods are wrong! It's just a matter of finding what works best for your DD.

Have you tried using the lattice method? While I'm not a huge fan of it, a bunch of my 6th grade students use it.
video - how to do lattice

Message edited 3/10/2011 8:18:40 PM.

Re: Math question(elementary) from a parent

Re: Math question(elementary) from a parent

I taught 4th grade for many years and we all thought Everyday math was crazy with it's crazy methods....

BUT

my students LOVED this particular way..called Lattice multiplication boxes
It was "their" way to multiply

They were able to multiply multi-digits with less error..

my students quiz scores were unbelievably different after I taught this way and they thought it was like a game! They actually enjoyed doing problems...

Here is a you tube video demonstrating it...it can be used for 3 digit by 2, 2 by 2, 3 by 3 etc!

WORTH A SHOT!!

Lattice Multiplication Box Method

ETA: sorry must have been typing mine will the above posted! HAHA!


ETA2:Another method we had to teach them....(then they got to chose which they liked better was
Partial Product Method

Message edited 3/10/2011 9:10:55 PM.

Re: Math question(elementary) from a parent

This is break away method is actually called the partial products method. Since you are trying to multiply 736 x 47, You need will to break apart 736 like this:
700+30+6

And the 47 like this
40+7

You will do the multiplying in 'parts' and then you will add the parts together to get the answer to your original equation. It goes something like this..

Since you are multiplying the large number by 47 you must break the 47 into 40 + 7. Starting with the 40 multiply it by the 700, 30 and the 6:

40 (700) 28000
40 (30) 1200
40 (6) 240

Now because they are in parts you will have to add them together
28000+1200+240= 29440

Now take the '7' from 47 and multiply it to 700, 30 and 6

7 (700) 4900
7 (30) 210
7 (6) 12

4900+210+12= 5152

Now take the two parts and add them:
29440 + 5152=34592

Same as if you did 736 x 47 out right.

They teach this way because it easier to multiply zeroes...just count the zeroes in the equation and then multiply whats left:
700 x 7 =
there are two zeroes so I know my answer will have two zeroes so now I just have to figure out 7 x 7
4900.
I hope this helps a little...I taught 4th in the city last year. this is one of many strategies.....they are not enforced but putout there so that kids can find what is comfortable for them and how they choose to solve the equation,

Message edited 3/10/2011 9:18:07 PM.

Re: Math question(elementary) from a parent

736x47

Okay, I teach my kids to use place value.

736 is broken into 700, 30, 6

47 is broken into 40, 7

Basically, you will be multiplying the 700, the 30 and the 6 by 40, THEN by 6 and add all of your answers.

What makes this work is the zeros trick and basic multiplication facts.

First, do:
700 x 40 But it's really 7x4 with 000 at the end (00 from 700 and 0 from 40).
28,000

Then do 30 x 40, but it's really 3x4 with 00 at the end.
1200

Then do 6X40 but it's really 24 6x4 with 0 at the end.
240.

Now take those same numbers and multiply by 7.

So, 700x7 becomes 7x7 with 00 at the end.
4900

30x7 becomes 3x7 with 0 at the end.
210

And 6x7 which is 42.

Then add all of the numbers together.

28,000
+ 1200
+ 240
+4900
+ 210
+42

Which equals 34592

Re: Math question(elementary) from a parent

Maggiebaby...great minds think alike!!!

When I taught summer camp/school, I taught the the old fashioned method, the lattice method, the method and I also showed the method using base 10 blocks. Like she said, it allows them to use the method that works best for them.