mental maths and numberlines

11 Plus Maths – Preparation and Information

Moderators: Section Moderators, Forum Moderators

Post Reply
fatbananas
Posts: 1411
Joined: Mon Mar 08, 2010 2:03 pm

mental maths and numberlines

Post by fatbananas »

Hello,

Can someone tell me if, when adding, say, 56+38, it is best to learn to do lots of this sort of question with number lines first, so that you can mentally picture the numberline at some point and do these sums mentally? My year 3 DS seems to be imagining the numberline in this way: 56 + 30 and getting to 86 quickly but then has to practically count on his fingers to add the remaining units, instead of being able to mentally bridge the 10 on a numberline and so on.

Hope that made sense :oops: . I just wondered if doing lots of these sums with a numberline would help him to finally get it mentally, or whether there was a more efficient method.

Thank you!
Seize the day ... before it seizes you.
Guest55
Posts: 16254
Joined: Mon Feb 12, 2007 2:21 pm

Re: mental maths and numberlines

Post by Guest55 »

Yes - number lines are a good support -

I'd encourage him to tackle 56 + 38 by one of

* 56 + 30 = 86 then + 4 to get 90 then add the remaining 4 (this avoids bridging the ten)

* adding on 40 and subtracting 2 - it's quicker!
fatbananas
Posts: 1411
Joined: Mon Mar 08, 2010 2:03 pm

Re: mental maths and numberlines

Post by fatbananas »

Thanks so much Guest55. I thought adding units to the nearest 10, in this case 90 and then adding on til you've added all the remaining units, was called 'bridging through 10'! :oops:

and, yes, I can see that adding 40 and subtracting 2 is far better - much quicker. Thank you!
Seize the day ... before it seizes you.
Guest55
Posts: 16254
Joined: Mon Feb 12, 2007 2:21 pm

Re: mental maths and numberlines

Post by Guest55 »

You can call it bridging through 10 ... :D

http://ictgames.com/bridgingThro.htm" onclick="window.open(this.href);return false; has some games about it ...
fatbananas
Posts: 1411
Joined: Mon Mar 08, 2010 2:03 pm

Re: mental maths and numberlines

Post by fatbananas »

They look great games. Thank you very much!
Seize the day ... before it seizes you.
yoyo123
Posts: 8099
Joined: Mon Jun 18, 2007 3:32 pm
Location: East Kent

Re: mental maths and numberlines

Post by yoyo123 »

Guest55 wrote:You can call it bridging through 10 ... :D

http://ictgames.com/bridgingThro.htm" onclick="window.open(this.href);return false; has some games about it ...
I've used the catapult one with y5/y6 children who found it hard to visualise and it was very useful
fatbananas
Posts: 1411
Joined: Mon Mar 08, 2010 2:03 pm

Re: mental maths and numberlines

Post by fatbananas »

Thanks for the pointer, Yoyo :D
Seize the day ... before it seizes you.
Post Reply