Lesson video

Hi everyone, thank you for joining me.

My name is Ms. Jeremy and today's Math lesson is based on rounding six digit numbers to the nearest 1,000, 10,000 and 100,000.

So, get yourself a nice, quiet position for your learning, and once you're ready, press play to begin the lesson.

So, let's go through our lesson agenda first of all, we're going to begin with a warmup where we look at rounding to the nearest 100,000 and 10,000.

Later on in the lesson, we're going to look at rounding to the nearest 1,000, and we're going to end with some mixed rounding and your independent task and quiz.

For this lesson, you will need a pencil and some paper.

You'll also need a nice quiet space, free from distractions.

So, pause the video now to get all of your resources ready and once you're ready, press play to begin the lesson.

Okay, let's start by looking at our warm up question.

The question asks, how would we round this number to the nearest 100,000 and to the nearest 10,000? So, we're doing two different things.

We're going to start with that first thing that's written in the pink.

I'm going to round this number to the nearest multiple of 100,000.

Let's say the number together, it's 671,453.

And because I'm rounding to the nearest 100,000, I am focusing on that digit that's in the 100 thousands column, I'm focusing on the six.

So, I need to work out whether this is going to round up to the next 100,000 or round down to 600,000.

I'm going to follow my steps to success to help me with this.

First thing's first, I'm going to place both of my multiples of 100,000 on either end of my number line.

So, on this side here, I'm going to need to write 600,000.

On this side here, I'll be writing 700,000 and halfway between, my halfway point is 650,000.

And now, I'm going to play 671,453 on my number line.

So, if I know 650,000 is there, that would be 660,000 670,000.

So, 671,453, I'm estimating to be around that position there, and straightaway I can see that that number is far closer to 700,000 than it is to 600,000.

So, therefore this number rounds up to 700,000.

Okay, that's the first part done.

Now, let's try and do the next part.

So, I'm going to rub out our marking because we're going to need to use different points on our number line, because this time we're rounding to the nearest multiple of 10,000.

So, this time I'm focused on that digit that's in the 10 thousands place.

I need to put both of my multiples of 10,000 on either side.

So, here I go.

Here's 670,000, that's the smaller multiple.

What do you think the larger multiple's going to be? It's 680,000, that's 10,000 up.

So, I'll write that on this side here.

And which number or what number, sorry, is halfway between 670,000 and 680,000? Going to give you three seconds to work it out.

Okay, have you got it? It's 675,000.

So, that is halfway between.

I need to work out where to place 671,453.

Well, again, I'm going to count up, but this time in my thousands because each of my small intervals is equivalent to 1,000.

So, here's 670.

Here's 671,000, and I reckon 671,453 is around there.

Much, much closer to 670,000.

So, in this case, my number rounds down, my number rounds down to 670,000 when rounded to the nearest 10,000.

So, that should give you a little recap of how to round to the nearest 100,000 and to the nearest 10,000.

We'll be using that knowledge today but we're also going to be looking at rounding to the nearest 1,000.

So, let's have a practise of that.

So, here's my six digit number, 671,453.

But this time I'm looking at the digit that's in the one thousands column.

Again, I'm referring back to that same success criteria, it's exactly the same.

The only thing that changes are those multiples of 1,000 on either end.

In the first example, we were looking at multiples of 100,000.

Then we looked at multiples of 10,000 and now, because we're rounding to the nearest 1,000, our multiples will be the multiples of 1,000 on either side of our number line.

So, on this side here, I've got 671,000.

And I'm going to need to count 1,000 up to work out, which number's on the other side of my number line.

What is 671,000 plus 1,000? It's 672,000.

And you can see I'm just writing that there.

The number that is halfway between these two multiples is? 671,500.

And I'm going to be placing my number on the number line.

So, let's count upwards.

I think I'm going to be starting with my lower, smaller multiples.

So, let me start here.

And I'm counting up in hundreds this time 'cause my small intervals are equivalent to 100.

671,000 671,100, 671,200, 671,300, 671,400, and so, 671,453 is just there.

Well, approximately just there.

And you can see that even though it's really close to my halfway point, it's not quite there.

So, this number is actually going to round back down to 671,000.

Now, I'm going to show you something that I could have looked at without drawing my number line to help me with this.

If I wanted to, what I could do, is I could look at the digit that features after the thousands place.

And I can see that digit is a four.

Now, if I remember, that anything that is four or lower, I round down four.

Or anything that is five or higher I round up four, then I could have used that to tell me already that we would be rounding this number down to 671,000.

And I've used my approximately sign there, my wavy equal sign, to demonstrate that we are approximating this value or rounding this value and the rounded answer is 671,000.

So, now I'd like you to have a go at the same strategy that I've used to round to the nearest multiple of 1,000.

You've got the number 403,576, and I'd like you to use the number line method, using the steps of success that I have on the screen here to work out whether this rounds up or down.

One thing I would like you to do just before you begin is to have a quick look at the strategy I showed you where you have a look at the digit that is next to or is on the right of the number that you're rounding, and see if you can predict whether you'll be rounding up or down based on the fact that that digit is a five.

Have a think about that before you draw your number line and then complete your rounding.

Pause the video to complete your task and resume it once you're finished.

Okay, how did you get on? Let's have a little look at this together.

So, first of all, let's go back to that strategy, that sneaky top tip for predicting whether a number's going to round up or down.

I had a quick peek at the number that was next door to my three thousands, and I saw that it was a five and I reminded myself that anything that is a five or above rounds up.

So, my prediction is, this number is going to round up to the next thousand, rather than rounding down.

Let's use the number line method to see whether I'm correct.

So, what you should have done first of all, is placed your different multiples of 1,000 on either side.

So, here, this is 403,000 and this side we've got 404,000.

Halfway through, we've got 403,500, and now, we're going to place 403,576.

Very, very close, the number's very close to my halfway points.

So, 403,500 is here, and so, I would estimate that it's going to sit around that point there and just like I predicted, interestingly, my number is rounding up because it's closer to the 404,000 on the other side of my number line.

So, therefore, we can say using our approximately sign 403,576 is approximately equal to 404,000.

How did you get on with that activity there? Let's move on, let's make it a little bit more challenging.

So, what I want us to look at is mixed rounding as well.

What we can do is we can actually round numbers to the nearest 1,000, 10,000 and 100,000, and we can use a number line to do so.

I'd also like us to use our top tip, to see if we can predict whether the numbers will be rounding up or down without drawing the number line first.

So, I'm going to do an example with you together now, then I'm going to ask you to do your own example afterwards.

Let's get started with this number here.

872,355.

We're rounding to the nearest 1,000 first of all.

So, I'm going to start with my prediction, I'm going to underline my digit in the one thousands column, and I'm going to take a sneaky peek at the number that is on the right, the hundreds column.

That's going to help tell me whether we're rounding up or down.

I can see that this digit is a three, suggest to me that we are probably going to be rounding down for this particular example, but I'm going to use my number line to double check.

So, let me put in my different multiples of 1,000 on either side of my number line.

So, on this side here, I'm going to need to put 872,000 because that's my smaller multiple of 1,000.

On this side, I'm going to put 873,000, that's my larger multiple, and my halfway point is 872,500.

And now, I'm going to place my number on my number line.

So, I can see the 872,355, it's going to be placed around here.

And straightaway, I should be able to see that I will be rounding this number down to 872,000, because it is closer to that multiple than it is to 873,000.

So, our prediction was correct.

So, we've had a go at the first example.

Let's see whether we can round to the nearest 10,000.

I'm going to need to rub out all of my markings because this time we're not focused on the thousands column, we're going to be thinking about the 10 thousands.

And I'd like you to have a little think about the strategy that we're going to use for this.

So, the first thing I'm going to need to do is underline the digit in the 10 thousands, that's the seven and have a sneaky peek at the next number along, which is the two.

So, I can see straight away that I'm probably going to need to round down, but I am going to double check by using my number line method.

This time I'm using my multiples of 10,000 on either side of my number line.

So, I'll start with 870,000 just here.

And on this side, I'm going to have 880,000.

And then in the middle, I'm going to have my halfway point, I'm going to give you three seconds to work out your halfway point for the middle point here.

So, my middle point is 875,000.

Now, placing my number on my number line, I got 872,355.

So, that will be around this point here, and just like my prediction did say, I am going to be rounding down, this number rounds down to 870,000.

Brilliant, so, I've done my next step, let's see if we can do the final one.

Once again, I'm going to need to rub out all of my markings because we are shifting our number line ending, and starting and ending points.

So, this time, I'm focused on the digit that's in my hundred thousands column, that's an eight, that has a value of 800,000.

I'm going to take a sneaky peak at the next door number, and that will help me make a prediction about whether I'm rounding up or down.

In this case, it's a seven, and I'm remembering that actually anything that is a five or above is rounded up.

So, in this case, the fact that it is a seven suggest to me that we are rounding up but let's make sure.

I'm going to put my different multiples of 100,000 on either side.

So, I've got 800,000 on this side, 900,000 on this side here, and halfway between, we've got 850,000.

Just like that.

Now, 872,000, well, if I know this is 850,000, this should be 860,000, 870,000.

So, 872,355 is around here, and you can see just like I predicted, we are rounding up, it's closer to 900,000 than it is to 800,000, and my prediction was correct.

So, there we have it, we've managed round to the nearest 1,000, 10,000 and 100,000 using a prediction and the number line method to double check.

So, it's your turn to have a go now.

We've got the number 651,298.

I'd like you to have a practise at rounding this number to the nearest multiple of 1,000, 10,000 and 100,000.

I'd also like you to try and use my little method to have a prediction or to make a prediction about whether you're going to be rounding up or down.

Spend a few minutes doing this now using a piece of paper.

Pause the video to complete the task and resume it once you're ready.

Okay, how did you get on? Let's have a look at the answers and see what you managed to find.

So, what you should have found that when you were rounding to the nearest 1,000, this number rounded to 651,000.

When you're rounding to the nearest 10,000, this number rounded down again to 650,000.

However, when we were rounding to the nearest 100,000, this number rounded up to 700,000, and I hopefully you've managed to use that little prediction method to help you work out, whether you'll be rounding up or down before checking with your number line strategy.

Okay, so, moving on to your independent task for today's lesson, what I'd like you to do is have a practise at rounding each of the numbers that you see on the screen to the nearest multiple of 1,000, 10,000 and 100,000.

I'd also like you to demonstrate what the smaller and larger multiples are for each number before completing your rounding.

So, let me just demonstrate what I mean first of all.

The first thing I'd like you to have a look at is we're going to look at this example just here.

And we're going to have a practise at rounding this to the nearest multiple of 1,000, first of all.

I'd like us first to work out what the smaller multiple, and larger multiples of 1,000 are.

So, remember, I'm looking at the digit, that is in the one thousands place, that's my five.

So, my smaller multiple in this case is going to be 325,000.

And my larger multiple is 326,000.

And your task is to identify whether our number is larger, it's going to round up to 326,000 or round down to 325,000.

You can use a number line to help you work this out if you'd like to, or you can use the strategy we spoke about earlier, where we have a little peek at the digit next door, and I can see this is going to round up.

So, in this case, this rounds up to 326,000.

For the next example, I'd be looking at the digit in the 10 thousands.

And for the final one, it would be the digit in the 100 thousands.

So, I'd like you to try and use the same strategy to answer all of the questions of question one and question two.

For questions three and four, I would like you to round each of those numbers to the nearest 1,000, 10,000 and 100,000.

You can just write them all in a row if you'd like to using either the number line method or the prediction method that we spoke about earlier on.

Pause the video to complete your task and resume it once you're finished.

Let's have a look at some answers.

These are the answers for the questions that you completed.

You can see here that I've got all of the rounded answers in a row, just there for you.

What I haven't filled in is the smaller and larger multiples, but hopefully if you've managed to find the rounded answer, you've managed to find the small and larger multiples too.

I've also got here for you, the answers to the questions related to questions three and four.

So, you can give yourself some ticks if you've got those correct.

So, we've reached the end of the lesson.

Thank you so much for staying with me.

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

Anything left to do now, is to complete your quiz.

Thank you so much for joining me for another Maths lesson today, it's been great to have you.

Do join me again for some more maths soon.

Bye bye.