Lesson video

Hello, my name is Mrs. Hopper, and I'm really looking forward to working with you in this lesson.

The lesson comes from our unit, "Introduction to division structures." So we're going to be looking at how we can divide numbers up.

Are you ready to make a start? If you are, let's get going.

In this lesson, we're going to be solving a variety of division problems and explaining understanding.

So you might have been looking at quite a lot of division recently, looking at different sorts of problems. So that's what we're going to be doing in this lesson.

We're going to be sorting them out and solving them.

We've got three keywords.

Equal, group, and share.

So I'm going to take my turn to say them and then it'll be your turn.

Are you ready? My turn, equal.

Your turn.

My turn, group.

Your turn.

My turn, share.

Your turn.

Excellent.

I hope you've been using those words quite a lot recently.

I'm sure you're very good at sharing things equally.

So let's look out for those words as we go through our lesson today.

And there are two parts to our lesson.

In the first part, we're going to be dividing by two, five, or 10.

And in the second part, we're going to be thinking about grouping and sharing problems, different ways to think about division.

So let's make a start on part one.

And we've got Aisha and Jun helping us with our learning today.

Aisha and Jun are looking at some division problems. Aisha says, "Should we divide by two, five, or 10? And they know that they can solve those divisions by skip counting in twos, fives, or 10s.

So I think they're going to sort some problems. Jun says, "We need to identify the whole in each problem." That's very true, Jun.

So here is our problem.

There are 30 legs.

How many crabs are there? And Aisha says, "Each crab has 10 legs.

30 is the whole.

That's the total number of legs." So Jun says, "We have to skip count in 10s.

We would calculate 30 divided by 10." 30 divided into groups of 10, 'cause we want to know how many groups of 10 legs we've got.

So for this problem we'd skip count in 10s 'cause we're trying to find out how many groups of 10 legs.

30 divided by 10.

What about this one? Five penguins share 40 fish.

How many fish do they each get? Ooh, it's one of our keywords is there, share, isn't it? Can you remember what it's like when we share things out? Well, Aisha says 40 is the total.

That's the whole, the number of fish shared between the penguins.

And Jun says, "We have to skip count in fives." Because we've got five penguins to share the fish between.

We would calculate 50 divided by five, 50 shared between five penguins.

So we'd skip count in fives for this one.

What about this one? 10 pandas get into pairs.

How many pairs are there? When you line up in pairs, how many of you are there together? Well, there's 10 in the whole.

That's the number of pandas.

But we'd have to skip count in twos because a pair of things is two things, isn't it? So we'd have to calculate 10 divided by two.

How many pairs are there? How many twos? So for that problem, we'd skip count in twos.

So let's work it out.

10 pandas get into pairs, how many pairs are there? Let's use skip counting to work out the number of pairs.

And we've just worked out we need to count in twos and we stop when we reach 10.

So are you ready to skip count in twos? Let's go.

Two, four, six, eight, 10.

And each of those counts is one pair of pandas.

So how many times did we count? Aisha says, "10 divided by two is equal to five." We skip counted five lots of two, didn't we? 10 pandas is equal to five pairs of pandas.

10 divided by two is equal to five.

Time to check your understanding.

There are 15 legs, how many seastars are there? And Aisha says, "Each seastar has five legs.

So should you skip count in twos, fives, or 10s?" And what division calculation should you do? So pause the video, decide on your skip count, and think about the division calculation.

And when you're ready for some feedback, press play.

How did you get on? Well, seastars have five legs and we want to find out how many seastars there were.

So we should skip count in fives.

How many groups of five are there in 15? And we should calculate 15 divided by five.

15 divided into groups of five this time.

So we're gonna skip count in fives.

Well done if you spotted that.

So let's solve the problem now.

There are 15 legs.

How many seastars are there? So each seastar has five legs, so you're going to use skip counting to work out the number of seastars.

Count in fives until you reach 15 and complete the equation.

Pause the video, have a go, and when you're ready for some feedback, press play.

How did you get on? Should we skip count and work out how many seastars there were? Five, 10, 15.

15 divided by five is equal to three.

Three seastars have 15 legs altogether.

So there were three seastars.

Time for you to do some practise.

You're going to sort the problems into the table.

You're going to write a division calculation to match each problem.

Should you divide by two, five, or 10? You could skip count to find each answer.

And here are the problems for you to sort.

So pause the video, have a go, and when you're ready for the answers and some feedback, press play.

How did you get on? So eight penguins get into pairs.

How many pairs of penguins are there? Well, we need to skip count in twos.

And if we skip count in twos, two, four, six, eight.

That's four pairs of penguins.

Eight divided by two is equal to four.

Two dogs share 12 biscuits equally.

For the next one, two dogs share 12 biscuits equally.

How many biscuits does each dog get? So this time, again, we need to skip count in twos because we've got two dogs.

And each time we count, each dog will get one biscuit.

So two, four, six, eight, 10, 12.

That's six counts of two.

So each dog will get six biscuits.

12 divided by two is equal to six.

For this one, there are 25 legs, how many seastars are there? We needed to skip count in fives because seastars have five legs each.

So we got to count up to 25 in fives.

Five, 10, 15, 20, 25.

That's five counts.

So there must be five seastars.

25 divided into groups of five is equal to five.

Then we had five mice sharing 10 nuts equally.

How many nuts do they get each? Well again, we're skip counting in fives because we've got five mice to share the nuts between.

So we can still skip count in five.

So five, 10.

That's two counts.

So each mouse gets two nuts.

10 nuts shared between five mice is equal to two nuts each.

Ah, now we had to skip count in 10s.

10 elephants share 50 bananas equally between them.

How many bananas does each elephant get? So we can skip count in 10s because there are 10 elephants.

10, 20, 30, 40, 50.

That's five counts of 10.

Each elephant gets a banana each time we count, so they get five bananas each.

50 bananas shared between 10 elephants is equal to five.

50 divided by 10 is equal to five.

And then we had to work out how many crabs there were.

Remember, crabs have 10 legs, so we had to skip count in 10s this time.

There were 20 legs.

10, 20.

Oh, that's two counts.

One count is each crab, so that means there are two crabs.

20 divided into groups of 10 gives us two groups of 10.

Well done if you've got all those in the right places and you've got the right answers too.

Great skip counting.

And onto the second part of our lesson, we're going to be thinking about grouping and sharing problems. So a division problem can be a grouping or sharing problem.

In a grouping problem, the whole is divided by the size of each group.

In a sharing problem, the whole is divided by the number of groups.

So let's have a think about that.

Aisha and Jun visit a zoo and they solve lots of division problems. So let's see, are they sharing or grouping problems? 20 children travel on a coach, off to the zoo, I think, and they sit in pairs.

"How many pairs of seats do we need," says Aisha.

And Jun says, "This is a grouping problem.

We want to know the number of groups of two in 20." So we want to know the number of groups, so we call this a grouping problem.

So we're going to solve 20 divided into groups of two is equal to our number of groups.

So let's count how many groups of two.

Two, four, six, eight, 10, 12, 14, 16, 18, 20.

We skip count in twos because our group size is two, but we want to know how many groups there are.

How many times did we count? It was 10, wasn't it? So we need 10 pairs of seats.

20 divided into groups of two is equal to 10.

The teacher puts 20 children into groups of five.

How many groups will there be? Well, this is also a grouping problem, isn't it? We want to know the number of groups of five.

So we're going to do 20 divided into groups of five.

We can still skip count in fives 'cause we want to know how many fives there are in 20.

Five, 10, 15, 20.

And you can see a group of five on each of our jumps.

So how many groups are there? Well, it's four, isn't it? 20 divided into groups of five is equal to four.

So there are four groups of five children.

20 divided into groups of five is equal to four.

There are 10 penguins at the zoo.

They are given 40 fish to share.

Oh, there's a clue there, isn't there? How many fish does each penguin get if they share them equally? This is a sharing problem.

We want to share 40 fish between 10 penguins.

We know we are making 10 groups of fish, one group for each penguin.

What we want to know is how many fish there are in each group.

And Jun says, "I'm going to skip count in 10s and I'll stop when I reach 40." One 10 is one fish each.

That's 10.

Two 10s is two each.

That's 20.

Three 10s is three each.

That's 30.

Four 10s is four each.

That's 40.

Each time we count a group of 10, each penguin gets one fish.

40 fish divided between 10 penguins is equal to four each.

They get one fish from each count of 10.

So the penguins get four fish each.

40 fish shared between 10 penguins is equal to four fish each.

Time to check your understanding.

There are five elephants at the zoo and they are given 30 bananas.

How many bananas does each elephant get if they share equally? And Jun says, "This is a sharing problem.

You need to share 30 bananas between five elephants." So skip count in fives, stop when you reach 30 and complete our calculation.

How many bananas will each elephant get? Pause the video, have a go, and when you're ready for the answer and some feedback, press play.

How did you get on? Should we skip count in fives? Five, 10, 15, 20, 25, 30.

How many times did we count? Six times, didn't we? So six groups of five is six each.

Each elephant gets one banana each time we count.

So 30 bananas divided between five elephants is equal to six bananas each.

30 divided by five is equal to six.

And this was a sharing problem.

We knew there were five groups of bananas we were going to make.

We didn't know how many bananas were in each group, but there were six.

Each elephant gets six bananas.

There are 50 strawberries.

Some raccoons share them equally and they get 10 each.

Ooh, now what's missing this time? We know the group size because they get 10 each, and we can see this is still a sharing problem, but we want to know how many raccoons shared the strawberries.

And Jun says, "We could write this as a missing number problem." 50 strawberries shared between some raccoons is equal to 10 strawberries each.

We know the size of the group, but we want to find the number of raccoons.

Jun says, "I'm going to skip count in 10s and I'll stop when I reach 50." So are you ready to count with him? 10, 20, 30, 40, 50.

What does each count represent? Each count represents one group of 10 strawberries, and we know that the raccoon's got 10 each.

So each count represents one raccoon.

"50 strawberries divided between five raccoons is equal to 10 each," says Aisha.

We counted five groups of 10.

So 50 strawberries shared between five raccoons is equal to 10 strawberries each.

I hope they enjoy their strawberries.

I like strawberries, do you? Here's another problem.

10 penguins get three fish each.

How many fish are there? Oh.

So this time, we don't know our whole number of fish that we started with.

So how many fish did the penguins share? Jun says, "We could write this as a missing number problem." The whole is missing this time.

So some fish shared between 10 penguins is equal to three fish each.

He says, "I'm going to skip count in 10s and I'll stop when each penguin has three fish," 'cause each time he counts 10, that will be one fish for each penguin.

So let's count with him.

One 10 is one each.

That's 10 fish.

Two 10s is two each and that's 20 fish.

Three 10s is three each and that's 30 fish.

Let's check the problem.

10 penguins get three fish each.

So that's it, isn't it? 30 fish divided between 10 penguins is equal to three fish each.

So our missing whole this time was 30 fish.

And Aisha says, "We could also work out the answer using multiplication.

Three times 10 is equal to 30." 10 penguins and three fish each.

So there must be, three times 10 fish, in total, 30 fish.

Time to check your understanding.

Five elephants get five bananas each.

How many bananas are there? How many bananas did the elephants share? And Jun says, "We could write this as a missing number problem.

The whole is missing." Some bananas shared between five elephants is equal to five bananas each.

Count in fives and stop when each elephant has five bananas.

Pause the video, have a go.

And when you're ready for the answer and some feedback, press play.

How did you get on? So one five is one banana each.

That's five bananas.

Two fives, that's two bananas each.

That's 10 bananas.

Three fives, that's three each, and that's 15.

Four fives is four each and that's 20.

Five fives is five each and that's 25.

And we know that there were five bananas each.

So we must have had 25 bananas divided by five elephants, and that's equal to five each.

So our missing whole number of bananas was 25.

Well done if you work that out.

And as Aisha says, "We could also have used multiplication to work out the answer." Five elephants get five bananas each.

That's five lots of five, and five times five is equal to 25.

Another way to check that we've got the right answer.

And time for you to do some practise.

You're going to solve each problem and you're going to use skip counting to help you.

So in A, six giraffes get into pairs.

So there are, hmm, pairs of giraffes.

And can you write the division that shows that problem? In B, 60 fish are shared equally between 10 penguins.

How many fish does each penguin get and what does the division look like? So complete a division equation for each problem, and do you need to count in twos, fives, or 10s? In C, 16 raccoons get into pairs.

So how many pairs of raccoons are there? In D, 45 bananas are shared equally between five elephants.

How many bananas does each elephant get? And in question two, you're going to solve each problem using skip counting.

These are some of the slightly different problems we were looking at.

So in A, some lions get into pairs, there are seven pairs.

How many lions are there? In B, 10 penguins get eight fish each.

How many fish are there in total? And in C, five elephants get 11 bananas each.

How many bananas were there? Complete a division equation for each problem.

And for each of these problems, do you notice that the whole is missing this time? And here are some number lines to help you.

So pause the video, have a go at solving the problems, and when you're ready for some feedback, press play.

How did you get on? So for one, we had, in A, six giraffes get into pairs, and there are three pairs of giraffes.

You needed to skip count in twos for this question.

So are you ready? Two, four, six.

That's three lots of two, so three pairs of giraffes.

Six giraffes divided into groups of two is equal to three groups.

And there's the number line.

In B, 60 fish are shared equally between 10 penguins.

So we need to skip count in 10s for this.

10, 20, 30, 40, 50, 60.

That's six counts.

Each penguin gets one fish from each count, so each penguin gets six fish.

60 fish shared between 10 penguins is equal to six fish each.

60 divided by 10 is equal to six.

In C, 16 raccoons get into pairs.

So again, we are skip counting in twos.

You need to find out how many groups of two are equal to 16.

So we can count in twos.

And we find out that there are eight pairs of raccoons.

We skip count eight lots of two to get to 16.

And in D, 45 bananas are shared equally between five elephants.

So this time we're going to count in fives, all the way up to 45.

And that's nine times.

And each time we count five, each elephant gets one banana.

So each elephant gets nine bananas.

45 bananas shared equally between five elephants is nine bananas each.

45 divided by five is equal to nine.

So in question two, we had a missing whole each time, didn't we? Some lions get into pairs.

There are seven pairs.

Well, there must be 14 lions.

And Jun's reminding us again, that it was the whole that was missing this time.

So there are 14 lions.

14 lions divided into groups of two is equal to seven groups of two.

Seven pairs of lions.

And Aisha says, "You could also use a multiplication." If we know we've got seven groups of two, then we know we've got 14.

In B, 10 penguins get eight fish each.

So we can count in 10s and we can stop when each penguin has eight fish.

So we could say one 10 is one each, that's 10.

And if we counted all the way up, we'd get to eight 10s is 80 each, and that's 80 fish.

And we skip count in 10s, so there are 80 fish.

And for C, five elephants get 11 bananas each.

And Jun says, "Counting fives and stop when each elephant has 11 bananas.

So that's 11 groups of five, so that must be 55 bananas.

Look at all those bananas.

55 bananas shared between five elephants is equal to 11 bananas each.

And we've come to the end of our lesson.

Thank you for all your hard work and your mathematical thinking today.

We've been solving a variety of division problems and explaining our understanding.

So we've learned that it's important to identify the whole in division problem, even if it's the whole that's not known.

Skip counting in equal steps can solve a sharing or a grouping problem.

In a grouping problem, the whole is divided by the size of each group.

And in a sharing problem, the whole is divided by the number of groups we are making.

You've worked really hard and I hope you've enjoyed exploring all sorts of different division problems. There've been a lot of animals involved, haven't there? I hope you've enjoyed feeding all the animals.

Thank you for all your hard work and I hope I get to work with you again soon.

Bye-bye.