column method for addition

(15 Posts)
christinarossetti Tue 25-Feb-14 19:07:38

Dd came home in a flap about this today. Seems to involve drawing some sort of grid?

The only column method I know is the carrying method us oldies were taught and Google hasn't enlightened me further.

Anyone know about this? TIA

MrsKCastle Tue 25-Feb-14 19:29:33

Not using a grid, no...There's a grid method which is commonly used for multiplication. confused

What year is he?

We would start by adding the units, tens and hundreds separately before moving on to the standard column method.

Like this:

423
+154

7 (3+4)
70 (20+50)
500 (400+100)

= 577

Is it anything like that?

We'd partition like Mrs K but set it out differently... (this never works with the lining up on here, but here goes...)

435 + 251

400 + 30 + 5
200 + 50 + 1
--------------------
600 + 80 + 6 = 686

christinarossetti Tue 25-Feb-14 19:48:46

She's y2. Yes, she's been taught the grid method for multiplication and it's not that.

Grid multiplication in year 2? She's doing well! smile

christinarossetti Tue 25-Feb-14 20:46:04

I think the whole class has done it? Not sure, just looked very new fangled compared to what I did at school.

I'll speak with the teacher if there are a number of possible answers, so that I don't show her a method that she hasn't been taught.

Thanks

maizieD Tue 25-Feb-14 23:27:52

What do the partitioners do if the numbers to be added were something like 456 + 247?
Just curious.

456 + 247

400 + 50 + 6
200 + 40 + 7
________
600 + 90 + 13 = 690 + 13 = 700 + 3 = 703 (many will go 600+90+13=703 in one step)

Once they are comfortable with the partitioning, they generally find the recombining stage to be quite straightforward. The 'carrying' aspect comes as second nature using this route, because the pupil is secure about place value.

17leftfeet Tue 25-Feb-14 23:54:42

Column method is how we learnt in the olden days (1980s)

clam Wed 26-Feb-14 19:54:49

And we still teach that "traditional" method - but it comes after the expanded method explained here.

pointythings Wed 26-Feb-14 21:49:24

Yes, that's how my DDs learned. It instils a secure sense of place value so that the 'traditional' method becomes much easier because it is rooted in real understanding of what the numbers mean.

PastSellByDate Fri 28-Feb-14 14:54:10

Hi christinarosetti

Hard to know what to suggests as you didn't provide age of your DC is or year - but I think what your DC may mean (especially if KS1) is that the teacher is making a grid for different numbers - units/ tens/ hundreds

So let's say you're DC is adding 16 + 17

Draw a horizontal line and then a perpendicular line through it extending down - so it's like a long t.

The left column has the heading TENS and the right column has the heading UNITS.

Now insert 16 and 17.

TENS UNITS
1 6
+ 1 7
-----------------
2 13

well that's a bit crazy - you can't have 13 in the units column - so leave the 3 (units) and carry the ten to the tens column

TENS UNITS
2 3
+ 1 0
-----------------------
3 3

you then have 3 tens and 3 units otherwise known as 33.

Teacher may also be deconstructing numbers using a table of 3 rows and 4 columns :

so 341 + 537

HUNDREDS Row - Column 1 write down 300/ Column 2 write down 500
TENS Row - Column 1 write down 40 and column 2 wirte down 30
UNITS row - column 1 write down 1 and column 2 write down 7

Now add two columns together for each row and write the answer in the 4th column of the row

HUNDREDS: 300 + 500 = 800
TENS: 40 + 30 = 70
UNITS: 1 + 7 = 8

Now add up the numbers in the 4th column:

800 + 70 + 8 = 878

These are my ideas about it off the top of my head.

If these make sense for your DC great - if not my advice is ask the teacher to show you a quick example of the method so you can help at home or check school website for the numeracy policy (although saying this I know our school still after 6 years of asking refuses to develop one).

HTH

PastSellByDate Fri 28-Feb-14 14:56:40

Sorry that didn't work out once I posted it:

TENS----UNITS
-1-----6
+--1-------7
---------
-2-----13

then carry the ten from the 13 in the units column (because you can't have 2 digits in the units column)
TENS----UNITS
-1-----6
+--1-------7
---------
-2-----13

-TENS----UNITS
--2--------3
+---1----------0
------------
--3---------3

3 TENS + 3 UNITS = 33

PastSellByDate Fri 28-Feb-14 14:56:58

still didn't work but hopefully you get the idea.

christinarossetti Fri 28-Feb-14 21:24:01

Thanks. They seem to have jumped from partitioning to the column method without the inbetween bits outlined above (she's Y2 btw and not 7 yet) which seems a bit odd.

I did ask her teacher and she explained it as the column method which I was taught at school (ie the 'carrying over').

Think it probably is a grid for units, 10s and 100s.

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