# Year 5 column addition and subtraction

Discussion in 'Primary' started by littlest4r, Oct 13, 2011.

1. ### littlest4r

I used to play a game with my year 5s to help them understand the importance of the hundreds tens and units columns. We played it as a class with the big foam dice, as a sort of treat during the plenary for good behaviour, but you could play it as a pair? Basically, they each get three boxes (a H T and U), and you take turns rolling the dice. The aim of the game is to get the lowest number possible. But you can place your number in your opponents box or your own. For example, if you rolled a 1, you might want to put it in your own H column, whereas if you rolled a 6 you could put it in your opponents H column to ensure their number was a big one. You keep rolling till both yours and your opponents boxes are filled. But, you could adapt this for subtraction. Each player could have 6 boxes (H T U in two rows, like a subtraction via column method), and at the end you could complete the subtraction. That way, they would not only have to think about where to place their numbers on the columns, but also which row as to get the smallest number they would want a large number on the bottom row. The winner would have the smallest number at the end (or make it the largest number at the end if you like!) I hope that wasn't too confusing, it's quite hard to explain the game in writing!!! Good luck

2. ### alea

The problem is that they aren't ready for column addition and subtraction - they clearly don't have a concrete grasp of place value. Can they calculate accurately using number lines? If not then take them back to this. If they can use a number line confidently then they are probably ready to be introduced to expanded methods for addition and subtraction. For subtraction children need the decomposition to be demonstrated clearly with place value apparatus (such as Dienes) and then I would have them doing lots of practise using the Dienes (to decompose the tens etc) and if you're just working with 2 you will be able to check their understanding of what they're doing by listening to how they explain their working.
No. They don't need games. They need to understand. They're not ready to practise yet. And please try not to call their subtraction calculations 'sum' or when they are asked to find the sum of.... they will think they need to subtract!
Good luck

3. ### mystery10Occasional commenter

What level are they? What do they understand about addition and subtraction? And why do you have to add to subtract - you don't have to - what method are you talking about?
Can they add in tens and units in columns? Do they understand money calculations using 10p pieces and 1p pieces? Do you have a TA who is good at knowing all the different steps children should have gone through to get to this point and who can work out which bits are missing from these two children's "toolkits"? It's probably very hard in class to work out exactly what their sticking point is. Maybe the particular method you are using does not help their understanding and you need to think of something else.
Have to say that some of these written methods involving loads of steps are probably harder in some ways to some children than just seeing how you add units and tens in columns ------- really if you understand place value, and you've done some mental addition and subtraction where you split the numbers up into tens and units and add them all up in bits, the column method follows on quite logically without writing down gazillions of partitions.

4. ### wizbit81

Thanks for the comments, keep them coming! I'd just like to say that I am helping this group on a voluntary basis following the class teachers instructions, the three children I am working with are significantly behind their peers. We have done a lot of place value exercises and discussions which they seem to understand but when it comes to the column addition and subtraction tasks they seem to lose their confidence. One of the boys is still struggling with adding single digit numbers so we have done some number bonds work.

5. ### minnieminxNew commenter

You need to feed this back the the class teacher. If a child struggles with single digit subtraction then they are not at a point to do column subtraction...totally pointless asking them!

Stick with using numberlines. For year 5 children significantly behind the class, I'm assuming they are working at level 2 and so totally unready for column calculations.

They need to be starting from where they are at, and the class teacher needs feedback from you as to where this is. They definitely don't need games to practise skills that are beyond where they are.

6. ### mystery10Occasional commenter

Might not be level 2 even. I help out one to one with some year 5/6 children. It's only now that I have my own children passing through KS1 that I realise they are struggling with some things that some reception / year 1 children can do.
It's interesting what volunteers get asked to do. The stuff I do doesn't fit with what they are doing in class at all. I am just told to plough through publications from Power of 2 publishing. Like you I don't really have a clue what these kids can or can't do until I hit a "wall", then I try to think of a different way of explaining it next time I go back. There's no communication with the class teacher. "Intervention work" is organised by the SENCO and she leaves it that way, which can be a little problematic. As the years have progressed I've become a bit more gung-ho about doing things my way as no-one seems to pay any attention to what I have done, they just seem to want a tick on a sheet to show that someone has done something one to on with the child that day or week.
This is the way that addition has progressed for my own children ..........
Addition using counting on and pre-drawn number lines - start with the larger number so there is less counting on to do, or less hopping along the number line
Learning number bonds to ten "off by heart" - but some of the year 5s never seem to get to this point
Number bonds to 20, number bonds to 30
Counting in tens from any given point
Adding using number bonds e.g. 7 + 5 - I know that 7 plus 3 makes 10, so 7 + 5 makes 2 more than 10 which is 12 ......... that involves a lot of knowledge of number facts for it to be a slick method - seems to get better by playing games etc
Doing lots of money counting with 10p pieces and 1p pieces, finding the smallest number of coins that can make up a particular amount and writing it down as tens and units e.g. 34p is 3 ten pence pieces and 4 pennies (smallest number of coins you can make it up from with ten pences and 1 pences)
Adding two digit numbers mentally by adding the tens first and then the units e.g.42p plus 37p.
Adding the tens - 40p plus 30p = 70p
Adding the units 2p plus 7p = 9p