To Calumetteach - ProTeacher Community
 Join the conversation! Post now as a guest or become a member today.

ARCHIVE

To Calumetteach

>

 Suezie Joined: Sep 2005 Posts: 3,930 Senior Member
Suezie

Joined: Sep 2005
Posts: 3,930
Senior Member
To Calumetteach
01-01-1970, 12:00 AM
 #1

What you are actually doing is teaching the children to understand "how" numbers work instead of the algorithm. This is a good method that allows the children to understand place value and how numbers behave. It is also a good method that teaches mental math. I use this method all the time as an adult. (P.S. The answer should be is 182).

I often explain to the children that we can manipulate numbers if we understand how they work. For example, lets say the question is:

1000
-742
-----

I teach the children to lower the 1000 by 1 (999) and do the same with the number they are substracting (therefore, 742 become 741).The problem is easier to do (less regrouping for the zeros) and there is less of a margin for errors. The "difference" between the two numbers is the same:

999
-741
-----

Hope this helps.

(This is weird, my post seems to be at the top of this thread instead of the original poster's)

 Leigh Guest
Leigh

Guest
03-23-2006, 04:58 PM
 #2

My second graders are really having trouble with this concept...especially subtracting with regrouping. How do you explain this concept? I tried using manipulatives but that just confused them even more....Any ideas or games that I could use to help them?

 NCteacher Joined: Feb 2006 Posts: 5,968 Senior Member
NCteacher

Joined: Feb 2006
Posts: 5,968
Senior Member
Regrouping....
03-23-2006, 06:03 PM
 #3

is so tough! I think I actually found this rhyme I used on this eboard. It goes....."More on the top? No need to stop! More on the floor, go next door, borrow 1 ten more! Numbers the same? Zero's the game!" My kids love saying it. We used linking cubes to help regroup. They had a work mat divided into ones and tens (we later added hundreds). I would give them a problem, such as 23 - 16. We would show two tens and three ones...then try to take 6 ones away from 3.....used the rhyme, went next door, borrowed a ten, broke the cubes up and moved it to the ones place. Then we could finish the problem. It needed a lot of repetition, but it seemed to work. Hope this helps!

 PrivateEyes Joined: Oct 2005 Posts: 3,822 Blog Entries: 5 Senior Member
PrivateEyes

Joined: Oct 2005
Posts: 3,822
Senior Member
Bingo chips
03-23-2006, 06:20 PM
 #4

Here's an idea I got from a website which was very helpful to me when explaining regrouping across zeros. I'm going to quote just a bit and give the link.

"We have these three different color poker chips, white ones, blue ones, and red ones. Whenever you have ten white ones, you can exchange them for one blue one; or any time you want to exchange a blue one for ten white ones you can do that. And any time you have ten BLUE ones, you can trade them in for one red one, or vice versa." Then you can show them how to count ten blue ones (representing ten's), saying "10, 20, 30,...,90, 100" so they can see, if they don't already, that a red one is worth 100. Then you do some demonstrations, such as putting down eleven white ones and saying something like "if we exchange 10 of these white ones for a blue one, what will we have?" And the children will usually say something like "one blue one and one white one". And you can reinforce that they still make (i.e., represent) the same quantity "And that then is still eleven, right? [Pointing at the blue one] Ten [then pointing at the white one] and one is eleven." Do this until they catch on and can readily and easily represent numbers in poker chips, using mixtures of red, blue, and white ones. In this way, they come to understand group representation by means of colored poker chips, though you do not use the word representation, since they are unlikely to understand it.

Let the students get used to making (i.e., representing) numbers with their poker chips, and you can go around and quickly check to see who needs help and who does not, as you go. Ask them, for example, to show you how to make various numbers in (the fewest possible) poker chips -- say 30, 60, etc. then move into 12, 15, 31, 34, 39, ... 103, 135, etc. Keep checking each child's facility and comfort levels doing this.

Then, when they are readily able to do this, get into some simple poker chip addition or subtraction, starting with sums and differences that don't require regrouping, e.g., 2+3, 9-6, 4+5, etc. Then, when they are ready, get into some easy poker chip regroupings. "If you have seven white ones and add five white ones to them, how many do you have?" "Now let's exchange ten of them for a blue one, and what do you get?(18)" Add larger and larger numbers and also show them some easy subtractions -- like with the number 12 they just got before, with the blue one and the two white ones, "If we wanted to take 3 away from this 12, how could we do it?" [Someone will usually say, or the teacher could say the first time or two] "We need to change the blue one into 10 white ones, then we could take away 3 white ones from the 12 white ones we have." ETC. Keep practicing and changing the numbers so they sometimes need regrouping and sometimes don't; but so they get better and better at doing it. (They are now using the colors both representationally and quantitatively -- trading quantities for chips that represent them, and vice versa.) Then introduce double digit additions and subtractions that don't require regrouping the poker chips, e.g., 23 + 46, 32 + 43, 42 - 21, 56 - 35, etc. (The first of these, for example is adding 4 blues and 6 whites to 2 blues and 3 whites to end up with 6 blues and 9 whites, 69; the last takes 3 blues and 5 whites away from 5 blues and 6 whites to leave 2 blues and 1 white, 21.) When they are comfortable with these, introduce double digit addition and subtraction that requires regrouping poker chips, e.g., 25 + 25, 25 + 28, 23 - 5, 33 - 15, 82 - 57, etc.

http://www.garlikov.com/PlaceValue.html

The whole website is really useful.

 imafostermom Joined: Oct 2005 Posts: 143 Full Member
imafostermom

Joined: Oct 2005
Posts: 143
Full Member
regrouping
03-26-2006, 09:12 AM
 #5

bigger bottom better borrow

 Teach2 Guest
Teach2

Guest
money
03-26-2006, 06:00 PM
 #6

We used pennies and dimes for the subtraction. My students caught on pretty quickly this way. They were able to see that sometimes there weren't enough pennies to "give away" so they needed to trade one of their dimes in for 10 more pennies.

 Jeff Ball Guest
Jeff Ball

Guest
Teacher in TX
03-27-2006, 06:54 PM
 #7

Manipulatives are over rated. Do it the old fashion way just show them how to do it then just, practice, practice, practice and more practice. Give them several problems each day along with some of their homework. Most kids get "it" by just doing it over and over !

 mmw Joined: Sep 2005 Posts: 473 Senior Member
mmw

Joined: Sep 2005
Posts: 473
Senior Member

04-02-2006, 09:49 AM
 #8

I diagree that manipulatives are way overrated. We use pennies and dimes and the children catch on quickly. What happens is that when you move to the abstract, they aren't connecting what they know to the numbers on the paper.

I have 30 kids and everyone is comfortable with trading now. It takes practice.....

Guest

04-02-2006, 10:21 AM
 #9

In my class we use the rhyme that PrivateEyes posted only we sing it and have a short dance (think Motown type) that we also do. For adding we sing a version of the Jefferson's theme song:
"Moving on up to the ten's side, to the deluxe apartment in the sky" (We build the box for our tens when we sing the second half). Both really seem to have helped my kids. Good luck!

 Lisa E Guest
Lisa E

Guest
04-02-2006, 02:25 PM
 #10

This site is great for regrouping.

Go to Dositey.com, then k-2, then adding or subtracting with regrouping. I sent the site home so the kids could practice. I also have a great subtraction regrouping poem but it is in school. That really helped to refer to the poem each time.

Good luck

 Lisa E Guest
Lisa E

Guest
subtraction regrouping poem
04-02-2006, 02:27 PM
 #11

I found it online.

More on top?
No need to stop.

More on the floor?
Go next door,
Get ten more.

Numbers the same?
Zero's the game.

We acted each one out. checked the #'s and knocked and everything!

 calumetteach Joined: Oct 2005 Posts: 1,605 Senior Member
calumetteach

Joined: Oct 2005
Posts: 1,605
Senior Member
have you ever seen regrouping this way?
04-02-2006, 02:55 PM
 #12

Have you ever seen it done this way and are there any sites or programs to teach it this way? How would you do the subtraction part? I’m wondering what methods other schools or even countries use. I saw this done on somewhere and I’d be interested how successful it is.

136
+ 46

100 +(30 + 40) + (6+6)

100
70
+ 12

=172

 Kaylen Guest
Kaylen

Guest

04-08-2006, 10:14 AM
 #13

I have seen that before. It must have been when I was student teaching. I think maybe it was Everyday Math. I think it is a great alternative, but the whole regrouping process should still be taught.

Join the conversation! Post as a guest or become a member today. New members welcome!

>
ARCHIVE