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Subtraction with Regrouping...

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 nicoled81 Joined: Oct 2008 Posts: 70 Junior Member
nicoled81

Joined: Oct 2008
Posts: 70
Junior Member
Subtraction with Regrouping...
12-08-2010, 04:11 PM
 #1

I'm about to start this unit, any suggestions???

 Caralala Joined: Dec 2007 Posts: 292 Full Member
Caralala

Joined: Dec 2007
Posts: 292
Full Member
This is a great site to check,
12-08-2010, 04:29 PM
 #2

you can use this to model the regrouping. My students loved it last year!
National Library of Virtual Manipulatives:

http://nlvm.usu.edu/en/nav/frames_as...topic_t_1.html

you can set the place value to play with depending on your students' ability levels.

 Caralala Joined: Dec 2007 Posts: 292 Full Member
Caralala

Joined: Dec 2007
Posts: 292
Full Member
12-08-2010, 04:31 PM
 #3

Meant to give you the direct link to subtraction:

http://nlvm.usu.edu/en/nav/frames_as...topic_t_1.html

If you have a smartboard, it is a great interactive tool.

 multigrade Joined: Aug 2009 Posts: 11,757 Senior Member

Joined: Aug 2009
Posts: 11,757
Senior Member

12-08-2010, 05:13 PM
 #4

I just did this.
I used unifix cubes made into 10 bars and a tens/ones mat.
They watched me break apart a tens bar and place the pieces onto the ones side so many times, it's (hopefully!) stuck in their brains.
Now, when I'm writing it on the board, they say I have to regroup and break apart a ten.

 Rm2tchr Joined: Jul 2009 Posts: 59 Junior Member
Rm2tchr

Joined: Jul 2009
Posts: 59
Junior Member
regrouping
12-08-2010, 06:07 PM
 #5

I teach my students a little poem to determine if they need to regroup 2 digit subtraction problems. Of course we "always, always, ALWAYS start in the ones place" (this is what I say constantly with addition or subtraction)

The poem goes "More on the floor? Go next door. More on top? No need to stop." It helps get the idea into their heads and then I interject the vocabulary "regrouping" or "decomposing" (as I hear the new national curriculum is calling it!) and also explain that math vocabulary must be used in their BCRs.

 TeachNut Joined: Jul 2009 Posts: 5,600 Senior Member
TeachNut

Joined: Jul 2009
Posts: 5,600
Senior Member

12-08-2010, 06:25 PM
 #6

I use the poem too, however this is how I have it:

More on the top,
No time to stop.

More on the floor,
Go next door,
Get 10 more.

Numbers the same,
Zero's the game.

I also teach that Mrs. One bakes cookies and always takes left overs over to Mr. Ten (carrying in addition); well, in subtraction, Mrs. One is making cookies and needs more sugar so she goes and asks Mr. Ten for some and he gives her what she needs. It's a whole scenario where I knock on the board as Mrs. Ones would knock on the door and I talk in different voices for the places.

 ljsplmi Joined: May 2008 Posts: 419 Full Member
ljsplmi

Joined: May 2008
Posts: 419
Full Member
Borrowing
12-08-2010, 08:04 PM
 #7

I use this poem too. Best for learning this concept ever. I do have the children place a tiny dot on the biggest number in the ones place before saying the poem or else they just subtract backwards bottom to top to make it "Work".

 teachinfl Joined: Jun 2006 Posts: 80 Junior Member
teachinfl

Joined: Jun 2006
Posts: 80
Junior Member
starting next week
12-09-2010, 06:36 PM
 #8

Using pretzel sticks for tens and mini marshmallows for ones - we will be regrouping sticks for mini marshmallows - hoping this helps them understand it

 jahlenius Joined: Apr 2008 Posts: 41 Junior Member
jahlenius

Joined: Apr 2008
Posts: 41
Junior Member
Subtraction with regrouping
12-11-2010, 05:31 AM
 #9

After I teach the concept, I teach the song, "If it's smaller on top take a ten(clap, clap) If it's smaller on top take a ten(clap, clap)...if it's smaller on top, take a ten and start again, if it's smaller on top take a ten. Sung to the tune of :If your happy and you know it, clap your hands.... Good luck

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