# Teaching my year 1's to add 2, two digit numbers?!!!

Discussion in 'Primary' started by chocochick, Apr 22, 2012.

1. ### chocochickNew commenter

Hi everyone.I hope someone can give me some advice. I am planning on getting my Y1 HA chn to add 2 2 digit numbers this week and I was wondering how others have got chn to do this before? I was thinking of getting them to partition the second number into tens and units and then add to the first number but I think they may find this really confusing and also struggle to lay out their work. I would love to know how others have taught this?
Thank you

2. ### rainbowdrop86New commenter

I personally wouldn't get them to record it at this stage. My yr2's struggle to record it. If u do record, I would record as a number line. When teaching it, yes do as you said and partition the second number. I use bundles of straws when teaching place value and taught adding 2 digit numbers with them as well. So for 32 + 24 we have 3 bundles of ten straws and 2 single straws on one table, and 2 bundles of ten straws and 4 single ones on another table. My yr2's know to start with big number and add the smaller. So we'd look at adding the 2 bundles first (demonstrating adding ten twice on a hundred square) then adding the single straws.
Hope that helps

3. ### lardylegsOccasional commenter

If you have Numicon, you could get them to make numbers with it, e.g. 12 + 21, then show them how to put the 10s plates together first, then add the units plates. (They could draw round the Numicon if you want them to record. )

I'm doing this this week too but I am getting them to partition both numbers into tens and ones, not just the second.
Either using dienes (the wooden tens and ones) or mentally, with jottings if they want to. The mental process is along the lines of...
32+24
30+20=50
2+4=6
50+6=56
I will start with questions where the 'ones' are not totalling more than 9!
Some children will be just doing 30+20 type questions
I am also going to show them on a hundred sqare another day - down for 10s and across for 1s, and just couple of kids are ready for empty number lines. Hope it goes well .

5. ### impulce

I do the same, but with cubes.
Partition both numbers into sticks of ten cubes, and single cubes. Then add the tens together, then the ones. It also helps them to begin to see how 'carrying' works when the single cubes add up to more than 10 they become a ten and move into the tens.

6. ### just_keep_swimming

I did this with my HA last week. The children already knew how to make 2 digit numbers using the numicon. So when posed a question such as 23 + 35, one of the children suggested they could put the tens together and count those first, before counting the other numicon plates. Mine were happy do this practically for other examples (without bridging tens at this early stage) and then to record as a simple number sentence: just 23 + 35 = 58. I was working with this group so I could see their working out using their numicon plates - I like the idea of drawing round the numicon plates if they were working independently though.