Lesson video

Hello everyone I'm Mrs Crane and welcome to today's lesson.

In today's lesson we're going to be using, applying and consolidating skills to be recapping how to use column addition and columns subtraction.

So using that column method for both operations today.

In a moment, I'll go through all of the equipment we'll need so don't worry about getting that just yet.

How was your day? I hope it's nice and sunny where you are.

Today, I got completely soaked because it was raining.

If you can, can you please turn off any notifications on your phone or tablet or whatever device you're using to access today's lesson in.

And then can you please try and find somewhere nice and quiet in our homes where were not meant to be disturbed during today's session.

Hopefully, once you're ready we'll get started.

Okay then, let's run through today's lesson agenda.

So we're going to start off by recapping column addition.

Then we're going to recap the column subtraction.

Then it'll be time for your independent task today, which will be you using the column method.

And then your challenge today is can you find the missing numbers? So let's get started by doing some recapping.

Oh! before we get started, you will need a pencil and some paper for today's lesson.

So if you don't have those things already, please pause your video now to go get them so that you've got them ready for our learning.

Okay, welcome back.

Let's get started then.

So we're going to start off by recapping addition.

Now I'm thinking about how do I calculate using the column method? What's it really important that we do? Well, I know it's really important for one that we learn our columns up.

I know that it's really helpful if we can make a quick estimate of our answer so that we know that we're kind of close to answer or not.

I also know that it's really important that if I have to regroup, I need to mark it down.

So my equation says, well my question says, use column addition to find the sum of 3,872 and 7,000.

Oh no, it's not 769.

So I've got a four digit number and a three digit number.

So I've lined them up so that my ones, tens and hundreds columns are accurately lined up and then my second number that I'm adding here, I don't have anything there because it's zero because it's a place holder.

If you want to write zero in there, you can just to remind yourself that as a placeholder and there's nothing there, you don't have to.

So let's make a quick estimate.

I can mount 3,800 up to 4,000 and 700 up to a 1,000.

4,000 at 1000 roughly 5,000.

So I know that I'm not going to go too far wrong if I'm near that figure.

Now, which column do I start with for column method edition? Absolutely, I always start with my ones column so two add nine.

Is that going to need regrouping? what do you think? It is, when does the number in addition need regrouping? How do we know if it needs regrouping? Well, I know if it needs to regrouping because my number one would be 10 or greater.

So two add nine, create a number that's 10 or greater to increase the number 11.

So I need to regroup one of my tens here and I keep my one here.

Now seven on six does that create a bond that is greater than 10 or 10? Absolutely, It does.

It creates the number 13 and I actually have another one here.

I need to remember to add that.

So it creates number 14, that 14 represents 14 tens.

So I'm going to write in here one and the four here, one to represent the one hundred 4 to represent the four tens.

Now I can do seven add eight.

Oh! Is that guys need regrouping? Yes it is.

How did you know? Fantastic, creates a bond that is 10 or greater.

It creates the number 15, but I want to add one more so it creates the number 16.

So I'm going to put my six here and my one here to represent.

It's actually 16 hundreds, not just 16.

Now can I just do three add nothing is three? I can't.

I must remember to add that regrouped one here, so it's going to be three add one which is equal to four.

So my answer is 4,641.

Okay then, what I'd like you to do now is if you're feeling confident, I would like you to choose a method you're going to use to solve this addition here.

Then I'd like you to explain why you chose that method and work out your answer using the method that you've chosen.

You're not feeling so confident that's okay because we're going to go through how we would answer it together now.

So am choosing our method.

I'm choosing the column method because I think that's going to be the most appropriate and efficient method to use to solve this equation.

So I start with my ones column, eight add nine.

Is that going to create a bond such as 10 or greater? Absolutely, it's going to create the number 17.

So I put in my one here to represent one tens and my seven ones here.

two add nine add one.

Are those three numbers going to create a number that is greater than 10? They are 10 or greater, sorry.

So two add nine is going to give me 11 add one it's going to give me 12.

So I put in my one here and my two here, there are 12 hundreds so that represents one, no 12 hundred sorry, 12 tens that represents one hundred and two tens.

Now three add three.

Can I just do three out of the way? I can't, I have that add that regrouped one.

Three add three is six, add one a seven.

Did I need to do regrouping this time? No I didn't.

Why did I not need to do regrouping this time? Well, because the number seven is less than 10, so I don't need to regroup to fit in one column.

So here's my number seven.

And finally, my thousand 7,000 add 1000 is 8,000.

Did I need to add anything additional? I just don't because I didn't regroup.

Okay now, what we're going to do next is recap subtraction before it's time for you to do your independent task today.

So, let's have a look there.

We're going to use the column method for subtraction.

So what is it really important that I do when I'm subtracting? Well I need to line up my columns firstly.

I need to have a quick look to see if I'm going to need to regroup.

How do I know if I need to regroup when I'm looking at subtraction? What I know I need to regroup when I'm looking at subtraction if the number that is my part has a column which has got a greater digit in the same column, that's in my whole.

So here my five ones is greater than my three ones.

So I need subtract definitely, I need to regroup.

So let's get started then.

We always start with our ones column.

Three subtract five I can't do it.

So I'm going to regroup from my tens.

My eight tens is going to become seven tens and I'm going to have 13 ones.

13 ones subtract five, is going to give me eight ones.

Seven subtract eight, can I do that? No, I couldn't.

Originally, I had eight subtract eight, I didn't think I needed to regroup that but because of my regrouping in one column, I now need to regroup in another column.

So I now need to regroup my two hundreds to become one hundred and I'm going to have 17 tens.

17 takeaway eight, now I can do it and it leaves me with nine.

One take away nine hundred.

Can I do that? I can't.

I need to regroup, this time for my thousands column.

My nine thousand is going to become eight thousand and I'm now going to have 10 hundreds.

So I'm going to have 11 hundreds here, take away 9 hundred which is going to leave me with two hundreds.

And finally, eight subtract seven, which leaves me with one.

So my answer is 1,298.

Remembering here, I had to regroup multiple times because of regrouping in one column.

Now I'd like you to, if you're feeling confident, have a go at this equation here using whichever methods you think is going to be most efficient.

Now I'm going to choose to use the column method to answer my equation and I'm going to go through the answer and how we get to i now.

So I'm going to start with my ones.

Three subtract three is nothing.

Seven subtract nothing is seven.

Oh! This is quite straight forward so far.

Eight subtract seven, can I do that? I can so one and five subtract two, I can and it's a three.

Why did my equation here not require regrouping? Why did it not require regrouping? Well none of the digits and the part that we were subtracting from were greater than the digits that were in the whole within the same column.

So three isn't greater than three, zero isn't greater than seven.

Seven isn't greater than eight and two isn't greater than five.

So it didn't need to do any regrouping in that equation.

Okay then, I think it's time now for your independent task.

You're going to be consolidating using the column method.

So both addition and subtraction.

I'll talk you through what you're doing in an minute.

So, firstly I'd like you to have a go at these two equations here, doing the addition column method to solve these equations.

Then I'd like you to use the column method to solve these two subtraction equations.

Then your challenge today is your missing numbers.

Can you complete the missing boxes here and here? Close the video now to complete your task.

Remember to resume once you're finished so we can go through the answers together.

Okay then, what we're going to do next is we're going to have a look at how we answer those questions.

So, I'm going to use my pen and show you how I would answer them by writing on the screen today.

So I'm going to write 8,273 and I'm going to be adding 1,925.

Which column? Sorry my rooted lines are not brilliant.

Which column do I need to start with? Fantastic, I start with my one so three add five is equal to eight so I'm going to put there my eight.

My tens, seven add two is equal to nine.

Two add nine, Oh! I need to regroup because they create a bond kind of greater.

So I'm going to regroup and create the number 11.

Eight add one is nine, plus one is 10.

So today I'm going to have created myself a 10, not intended to but a five digit number.

So my answer is 10,198.

Next then, I'm going to do part B.

So I'm going to do 637 plus, let's look at how we line up our columns here 1,882 really important that they line up because we've got a three digit number and the four digit number.

Seven add two is nine, three add eight, Oh! I'm going to need to do some regrouping because my answer is 11.

Six add eight, add the one, is going to give me 15, so I regroup and I put in my one here and my five here and one add one is two.

So my answer is 2,519.

Let's have let them add subtraction answer.

So I'm going to write them in again.

So I've got 6,872 and I'm taking away 3,951 going to draw it in here and start my ones column.

To take away one is one.

Five, not five sorry, seven take away five is two.

Oh! I need to do some regrouping here because the number, my part is greater than my whole.

So my 6 thousand becomes 5 thousand and I have 18 hundreds.

18 take away nine is five, I can do that.

Five take aways three is two.

So my answer is 2,921.

And my last equation then is 6,027 subtract 573.

Again, really important I left out my place value and line up the right columns.

Seven take away three, can I do that? I can and It gives me four.

Two takeaway Seven, Oh no! I can't do that and I've got zero as a placeholder here.

So I'm going to have to regroup from my thousands.

Give me five thousand and 10 hundreds.

I now need to regroup for my 10 hundreds to be nine hundreds and 10 tens 12 subtract seven, can I do that? I can and it gives me five.

Nine subtract four, sorry.

Nine subtract five is equal to four Or I do it out of my hand quickly.

Five subtract nothing is equal to five.

So my answer is 5,454.

Okay then, let's have a look at the missing numbers.

So in my first equation here, my missing numbers are a nine here and nine in the tens column, a one in the hundreds column, and a seven in the thousands column.

And in B here and my subtraction, I should have a one in my tens column and not tens column, sorry.

That's my ones column clearly.

And nine in my tens column a zero in my hundreds column.

If you'd like to please ask your parent or carer to share your work from today on Twitter, by tagging @OakNational and using the #LearnwithOak.

Absolutely fantastic work today, especially when we have been switching between addition and subtraction using that column method and great detective skills to find those missing numbers.

Hopefully I'll see you again soon for some more fantastic math.

Don't forget to go and complete your quiz to show off all of your fantastic knowledge.

Thank you and bye bye.