Go to navigation
It is currently Mon Dec 05, 2016 6:41 pm

All times are UTC




Post new topic Reply to topic  [ 17 posts ]  Go to page 1, 2  Next
Author Message
PostPosted: Thu Oct 16, 2014 10:25 am 
Offline

Joined: Mon Mar 08, 2010 1:03 pm
Posts: 1413
With sums such as 25+24, or 36+11, are children encouraged to add the tens together first and then the units (looking out for number bonds as appropriate), and then adding together? Or do they work from a mental number line, adding 10s first and then the units (how would this work with number bonds such as 22+38, for eg?).

And when do they learn column addition?

Thank you! :)

_________________
Seize the day ... before it seizes you.


Top
 Profile  
 
PostPosted: Thu Oct 16, 2014 10:47 am 
Offline

Joined: Fri Feb 27, 2009 12:41 pm
Posts: 1595
Location: Gravesend, Kent
I can only tell you the way my son in Year 3 would add these numbers.

25+24 would be added together in his head by taking the 25 adding 2 lots of 10 then the 4 units

So 36+11 would therefore be 36 add 10 then add the extra 1

I know lots of children would add the whole 2nd number in a flash, but my son is average at maths, not super-clever, so he finds it easier to break the numbers down to start with.

As to whether this is the correct way or not, parents don't get to meet the Maths or Literacy set teachers until February!

Edited to add....sorry, I have no idea about column addition.


Top
 Profile  
 
PostPosted: Thu Oct 16, 2014 1:27 pm 
Offline

Joined: Tue Jul 21, 2009 9:56 pm
Posts: 8228
They are encouraged to do it lots of different ways - kind of depends on the teacher.

The way that I find mine are fastest .... until it gets undone again is only to partition the second number

so

56 plus 48

say in head 56 + 40 = 96

Then add the 8 to get 104

Can do same thing no matter how many digits and no carrying is really needed in your head. Can subtract the same way. i.e. first take away the thousands, then the hundreds then the tens then the units.

If they are crossing a "boundary" --- like 512 - 30 they might be thinking about it lots of different ways ...... guess you would practise by doing 510 - 10, 20, 30, 40 etc first.


They are supposed to do loads more mental arithmetic like this in the new national curriculum. Have you had a read of it year by year? But they don't prescribe how to teach it.


Top
 Profile  
 
PostPosted: Thu Oct 16, 2014 2:11 pm 
Offline

Joined: Fri Feb 27, 2009 12:41 pm
Posts: 1595
Location: Gravesend, Kent
I am very embarrassed to admit that I've just realised my son actually started in Year 4 last month! :oops:


Top
 Profile  
 
PostPosted: Thu Oct 16, 2014 3:50 pm 
Offline

Joined: Mon Mar 08, 2010 1:03 pm
Posts: 1413
Thanks Inkypinkyponk and Mystery! That's v helpful.

Don't worry Inky. I do exactly the same! :)

_________________
Seize the day ... before it seizes you.


Top
 Profile  
 
PostPosted: Thu Oct 16, 2014 3:59 pm 
Offline

Joined: Mon Feb 12, 2007 1:21 pm
Posts: 11938
Yo might want to look at the new Primary National curriculum - I think columnar addition is in Year 3.

https://www.gov.uk/government/uploads/s ... _FINAL.pdf


Top
 Profile  
 
PostPosted: Thu Oct 16, 2014 4:14 pm 
Offline

Joined: Mon Mar 08, 2010 1:03 pm
Posts: 1413
Thank you guest55.

_________________
Seize the day ... before it seizes you.


Top
 Profile  
 
PostPosted: Thu Oct 16, 2014 4:36 pm 
Offline

Joined: Mon Feb 12, 2007 1:21 pm
Posts: 11938
Two digits numbers are done mentally and it's only when you have three digits or lots of two digit numbers that some people would use column addition.

Questions are always set out horizontally at KS2 and GCSE so children/students are free to choose their method. Lots of my students do all addition mentally unless it is awkward.

24 + 25 is known as a 'near double' as the two numbers are close. You can double 24 and add 1 or double 25 and subtract 1 or .....


Top
 Profile  
 
PostPosted: Thu Oct 16, 2014 4:45 pm 
Offline

Joined: Mon Mar 08, 2010 1:03 pm
Posts: 1413
I see; thank you. That's really helpful.

_________________
Seize the day ... before it seizes you.


Top
 Profile  
 
PostPosted: Thu Oct 16, 2014 4:59 pm 
Offline

Joined: Tue Jul 21, 2009 9:56 pm
Posts: 8228
Yes, and with numbers ending 7, 8, or 9 child might be quite fast using the nearest multiple of 10 and then adjusting afterwards.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 17 posts ]  Go to page 1, 2  Next

All times are UTC


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
CALL 020 8204 5060
   
Privacy Policy | Refund Policy | Disclaimer | Copyright © 2004 – 2016