KS1 Maths

[Megatron]

Hi there, my DS is having real problems with his maths at school (he's in Y2).

They have to do number lines e.g. 231 + 652 + 404 =

they have to show how they work it out and he doesn't have a clue where to start with this. Until very recently he was bringing home very simple number lines which he had no problem with and there seems to be a very big jump from them to this and I don't really know how to show him how to work it out as I know they do it completely differently from when I did it years ago, and I don't want to confuse him even more!

Any advice would be greatly appreciated.

Is this a numberline question, or does he have to add the HTU?
So 200+600+400 =1200
30+50+0=80
1+2+4=7

Total is 1287

I think they do the units, so add the digits first (1+2+4=7), then same with tens (3+5+0=8), then repeat with the hundreds. Be worth checking with the teacher though so you don't confuse him.

I think I'd say add the hundreds, the tens and the ones.

200 + 600 + 400
30 + 50 + 00
1 + 2 + 4

then 1200 + 80 + 7

could he work that out to get 1287?

I think the others are right, they teach them to add tens as 30+50+00. D'oh!

Thank you so much ladies, he's finding it quite hard to get. He was trying to add in tens but getting v confused. This makes it easier for me to help him now!

if he is supposed to use a numberline to do it then you normally do it in stages. So you would start at 231 and then jump and add 600 and then 50 and then 2. And then you would do the same again - adding 400 and then 4.

My DD would use what her school call the "Step-by-step" method, basically what hocuspontas said. I don't think they would use a number line for it, will ask DD tomorrow as in bed now.

Add the hundreds = 1200,
Add the tens = 80,
Add the units = 7.

What I would say, though, is that to add the component parts together mentally is quite difficult for a lot of children who may not be secure on number bonds and place value etc, I doubt whether a lot of the kids in my DD's class could do it.

mrz will probably be along soon to tell us that her year 2's could do it in 3 seconds flat, whilst building a scale model of the Eiffel Tower and playing their flutes.

www.andrelleducation.co.uk/BMFreebies/CLICsample.zip

page 16 might help but it isn't a numberline method

Actually we are still working on adding 2 three digit numbers bridging 10

Well, if you look at that specific example it is a simple question because there is no crossing of the boundaries between HTU to make the answer.
Whereas 164+187 is .

number line method would be like oakmaiden

231 + 652 + 404 =

231 + 600 is 831, then add 50 is 881, then add 2 = 883

883 + 400 = 1283 then 1283 + 4 = 1287

he should draw a picture of what he is adding too, on the number line

so start from 253, then do a jump of 600 etc