Lesson video

Hello, I'm Miss Miah, and I'm so excited to be a part of your learning journey today.

I hope you enjoy this lesson as much as I do.

In this lesson, you will be able to use knowledge of multiplication to solve problems, and your key word is on the screen now, I'd like you to repeat it after me.

Skip count.

Fantastic, let's move on.

So this lesson is all about using our knowledge of multiplication to solve problems. So this lesson is made of 2 lesson cycles and our first lesson cycle is all about identifying group size and number of groups.

Then we're going to be moving on to solving word problems. So to the group size and number of groups, it's really important to identify what they are 'cause that can help us when it comes to answering questions in worded problems, and also help us identify the multiplication equation needed to solve the problem.

In this lesson, you'll meet Alex and Jacob.

Let's begin.

So there is a book sale at school.

Jacob says, "Cool! The books are being sold in different packs." Pack of 2 books, pack of 5 books, and a pack of 10 books.

Now Jacob has enough money to buy 3 packs of 5 books.

How many books would this be altogether? So on the screen here we can see 3 packs of 5 books.

So there are 3 packs and each pack has 5 books.

We can also skip count in 5s because each pack of books has 5 books in it.

So 5 books, 10 books, 15 books.

That also means 3 is a factor because that is how many groups or packs of books there are.

Now 5 is also a factor because that is how many books there are in each group or pack.

So by identifying the factors, we can calculate the product.

And remember, the product tells us the total amount within a multiplication equation.

So there are 3 packs of 5 books.

That is 3 times 5, which is equal to 15.

So I will have bought 15 books altogether.

So Alex has enough money to buy 3 packs of 5 books.

How many books would this be altogether? So there are something packs.

Each pack has something books.

Well, there are 3 packs and each pack has 5 books.

That means we can also skip count in 5s because each pack has 5 books.

So let's begin, let's start from 0.

0, 5 books, 10 books, 15 books.

That also means 3 is a factor because that is how many groups or packs there are.

Five is also a factor because that is how many books there are in each pack or group.

By identifying the factors, we can calculate the product.

So there are 3 packs of 5 books.

That means 3 times 5 is equal to 15.

There are 15 books altogether, 15 is my product.

I will have bought 15 books altogether.

Now Alex changes his mind.

He wants to buy 4 packs of 5 books.

How many books would this be altogether? So there are mm packs, each pack has books.

There are 4 packs, each pack has 5 books.

So again, it means we skip count in 5s.

And do you remember why? It's because each pack has 5 books.

So let's start from 0 and count on and skip count in 5s.

So 0, 5 books, 10 books, 15 books, 20 books.

That means 4 is a factor because that is how many groups or packs there are.

Five is a factor because that is how many books there are in each group or pack.

So again, by identifying the factors, we can calculate the product.

So there mm are packs of mm, that is something times something which is equal to something.

So there are 4 packs of 5 books.

That is 4 times 5, which is equal to 20.

So 20 is our product.

Alex says, I will have bought 20 books altogether.

Over to you.

So Miss Coe would like to buy 5 packs of 10 books.

Identify the factors.

Something is a factor and something is a factor.

Is it A, 5 and 10, B, 10 and 10, or C, 50 and 10? You can pause the video here and click play when you're ready to rejoin us.

So what did you get? Well, it's A, 5 and 10.

And that's because we know that there are 5 groups and in this case it's 5 packs and each pack has 10 books.

So 10 is the other factor.

Now Alex goes on to organise the packs of books he has bought.

What's the same and what's different? Well, you may have said that the number of groups are the same.

So there are 4 groups, but the amount of books in each group is different.

So in the first group we've got 5 books in each group.

And in the second groupings we've got 2 books in each group.

So to describe both of those images, we can say that the first row represents 4 times 5 because there are 4 packs of 5 books.

And in the second row we can describe it as 4 times 2 because there are 4 groups of 2 books or 4 packs of 2 books.

This means the product will be different.

So remember, in order to calculate the product, for the first one, we can skip count in 5s.

And that's because there are 5 books in each group.

So let's start with 0, 0, 5 books, 10 books, 15 books, 20 books.

So 4 times 5 is equal to 20, 20 is our product.

Now let's move on to row 2 and we'll start with 0, so 0 book, so 0, 2 books, 4 books, 6 books, 8 books.

So 4 times 2 is equal to 8, 8 is our product.

There are 8 books altogether.

Now Jacob comes along and he organises his books.

What's the same and what's different? Well let's have a look.

This time the number of groups is different.

So in the first row we've got 4 groups, and in the second row we've got 3 groups or 3 packs.

The amount of books in each group is the same.

So there are 5 books in each group or pack.

So that means again, the product will be different.

We can skip count in 5s.

There are 5 books in each group.

So let's start from 0.

So 0, 5 books, 10 books, 15 books, 20 books.

So the product is 20.

There are 20 books altogether in the first row.

Now in the second row we can also skip count in 5 because again there are 5 books in each pack.

So we'll start off from 0, 0, 5 books, 10 books, 15 books.

So the product is 15, 3 times 5 is equal to 15, there are 15 books altogether.

Over to you.

I would like you to identify the factors for the packs of books you see below.

So I can see packs of 10.

There are something packs of something books, the factors are something and something.

You can pause the video here and click play when you're ready to rejoin us.

So what did you get? Well, I'm having a look here.

I can see that there are 3 packs of 10 books and the factors are 3 and 10 because there are 3 packs or 3 groups, so that's one factor, and there are 10 books in each pack.

So 10 is my second factor.

Now using the image below, I'd like you to calculate the product.

So pause the video here and click play when you're ready to rejoin us.

So what did you get? Well, by looking at the books, I can see that each group has 10 books.

So that means I can skip count in 10s.

So let's start from 0 and do it together.

0, 10 books, 20 books, 30 books, 30 is the product.

So the factors are 3 in 10, 3 times 10 is equal to 30, which means there are 30 books altogether.

Great, let's move on.

So now we're going to use what we've learned and apply it in a different way, so make sure you're paying attention.

Miss Miah, so me, I buy something packs of 2 books.

There are 6 books altogether.

So how many packs of books did I buy? Well, we know that the product is 6 because there are 6 books altogether.

So this time we know what the product is first, hmm.

So we can pop that into our equation.

It's kind of like playing the detective.

What do you know? Let's find out what we know and then slot it into our equation so we can figure out what we need to find out.

So let's carry on.

Now we also know that 2 is a factor because there are 2 books in each pack.

So we have some groups of 2.

We are not sure how many groups of 2 though.

So we can pop the 2 into our equation as well because 2 is a factor, we can place it there.

Now we need to figure out what the missing factor is.

So to find the missing factor, we can skip count in 2s until we reach 6 to find the amount of packs.

Why are we skip counting in 2s? It's because there are 2 books in each pack.

So we need to figure out how many packs there are, complete the equation.

So let's do that now.

2, 4, 6, hmm, how many packs of books do you see? There's 1 pack, 2 packs, 3 packs.

So that means I bought 3 packs of 2 books.

So my final equation is 3 times 2 is equal to 6.

3 was the missing factor, I bought 3 packs.

Let's move on and do the same again.

So this time, Miss Coe buys something packs of 2 books.

There are 10 books altogether.

How many packs of books did she buy? So let's pretend we're investigating.

What do we know right now? Well, we know that the product is 10 because there are 10 books altogether.

I wonder where we can place that.

Well, we can place it after the equal sign because anything after the equal sign in a multiplication equation is the product or the answer.

So we could pop the 10 there.

Now we know 2 is a factor, and that's because there are 2 books in each pack.

So we can pop that into our equation there.

So 2 is our factor.

Now what we need to do is find the missing factor.

And to do that we can skip count in 2s to 10 to find the amount of packs.

So let's begin from 0.

0, 2, 4, 6, 8, 10.

Now let's look at the packs.

How many packs are there? 1 pack, 2 packs, 3 packs, 4 packs, 5 packs.

So that means Miss Coe bought 5 packs of 2 books.

So 5 was the missing factor and 5 times 2 is equal to 10, 10 is our product, over to you.

I'd like you to look at the question, choose the right equation to help you to solve the problem.

So Jacob buys something packs of 5 books.

He has 15 books altogether.

How many packs did he buy? Is it A, something multiplied by 15 is equal to 5, B, something multiplied by 5 is equal to 15, or C, something multiplied by 1 is equal to something? You can pause the video here and click play when you're ready to rejoin us.

So what did you get? Well, it was B, and this is because there are 15 books altogether.

That is the product.

Now there are 5 books in each pack, that is a factor.

Well done if you've got that correct.

Right, onto the main task for your lesson cycle.

For question 1, Miss Coe, Jacob, Alex and Andy buy a different amount of books.

For each person identify the factors and find the product.

So you have various amount of packs of books.

I'd like you to fill in the blanks and find out what the product is.

Question 2, 3 and 4.

I'd like you to answer the following questions by finding the missing factor.

So Miss Miah buys something packs of 2 books.

She has 12 books altogether.

How many packs of books did she buy? Question 3.

Jacob buys something packs of 2 books.

He has 20 books altogether.

How many packs of books did he buy? And question 4, Alex buys something packs of 5 books.

He has 35 books altogether.

How many packs of books did he buy? You can pause the video here and click play when you're ready to rejoin us.

So how did you do? For question 1, this is what you should have got.

So for the first box the factors are 4 and 2.

4 times 2 were your factors.

The product is 8, and you could have skip counted in 2 to find the product.

For the second box, the packs of 5, the factors are 4 and 5, 4 times 5.

The product is 20.

You could have skip counted in 5s to find the product.

For the third box, so the bottom left, the factors are 8 and 2, so that's 8 times 2 and the product is 16.

And lastly the factors are 4 and 10.

And that's because there are 4 groups and there are 10 books in each group or pack.

So that is 4 times 10 and the product is 40.

Well done if you managed to get all of that correct.

Now for question 2, let's have a look.

So Miss Miah bought something packs of 2 books she had 12 books altogether.

So we would've skip counted in 2s to 12 and then figured out how many packs that was.

So that would've been 6 times 2 is equal to 12.

I would've bought 6 packs.

Now for question 3, Jacob bought something packs of 2 books.

He bought 20 books altogether.

So 20 was our product.

And then after that you would've counted the amount of packs, that would've been 10 times 2 is equal to 20 so Jacob would've bought 10 packs.

For question 4, Alex buys 7 packs of 5 books.

He has 35 books altogether.

Now we know he's bought 7 packs because the product was 35 or 5 books in some packs.

So we don't know how many packs there were.

So what you should have done was skip counted in 5s all the way up to 35 and then you would've found that there were 7 groups of 5.

So 7 times 5 is equal to 35.

Now let's move on to our second lesson cycle to solve worded problems. So Jacob has organised Miss Miah's books, which of these would he be able to skip count? Now, set A has a pack of 10, pack of 9 and a pack of 8.

And set B has 3 packs of 5.

Now, set A is not made of equal groups.

Now that's important.

If the groups are not equal, we cannot skip count the total amount.

Now, set B has equal groups of 5 so we can skip count on in 5s.

Now Jacob has reorganised Miss Miah's books, which of these would he be able to skip count? Have a look, there's set A and there's set B.

What do you think? Well, set B is not made of equal groups.

So remember if the groups are not equal, we cannot skip count the total amount.

Whereas set A has equal groups of 5.

So we can skip count on in 5s.

Over to you.

So which of the following will you be able to skip count to find the total? Is it set A or set B? Have a look closely at the groups.

You can pause the video here and click play when you're ready to rejoin us.

So how did you do? Well set B was correct, and that's because there are equal groups of 5, whereas set A has 2 packs of 5 and then 1 pack of 4.

So there are 5 equal groups of 5 books, you can skip count in 5.

Now it is day 2 of the book sale.

Jacob buys 3 packs of books.

He buys 15 books.

How many books are there in each pack? We can trial skip counting in 2s, 5s, and 10s to find the amount of books in each pack.

So Jacob begins to count in 2s, 2, 4, 6.

Counting in 2s shows 3 times 2 is equal to 6, but our product is not 6, it's 15, so it's not packs of 2.

Now Jacob decides to count in 5s, 5, 10, 15.

(gasps) Ooh, counting in 5s shows 3 times 5 is equal to 15, which is our product.

So there are 5 books in each pack.

Moving on.

Now Alex buys 4 packs of books.

He buys 40 books.

How many books are there in each pack? Well we can try or skip counting in 2s, 5s, and 10s to find the amount of books in each pack.

So Jacob counts in 2s.

Now Jacob, trials skip counting in 2s first.

So let's see what happens, 2, 4, 6, 8.

Aw, hmm, counting in 2s shows 4 times 2, which is equal to 8, but our product is 40, not 8, so this isn't right.

Now Jacob counts in 5s, 5, 10, 15, 20.

Hmm, counting in 5s shows 4 times 5 is equal to 20, which is still not our product of 40.

So now Jacob counts in 10s.

Let's see what happens.

10, 20, 30, 40.

Counting in 10s shows that 4 times 10 is equal to 40.

So that means Alex bought packs of 10.

Over to you.

I'd like you to look at the question below.

What is the missing number that we need to calculate? So Miss Coe bought 10 packs of books, she buys 20 books.

How many books are there in each pack? So 10 times something is equal to 20.

Is it A, the product that we're looking for? B, the factor that we're looking for, or C, the answer? You can pause the video here and click play when you're ready to rejoin us.

So what did you get? Well, we are looking for the missing factor.

You need to find how many books are in each pack, which is the factor.

And in this equation we know what one of the other factors is, which is 10, because that's how many packs that Miss Coe bought, and the product which is 20, because she bought 20 books altogether, so we are looking for the missing factor.

Right onto the main task for this lesson cycle.

Question 1, which of the following will you be able to skip count to find the total? Write down the multi equation equation where possible.

So look carefully at the groups for each set.

For question 2, Jacob bought 12 packs of books.

He buys 24 books.

How many books are there in each pack? Question 3.

Miss Miah bought 5 packs of books.

She bought 50 books.

How many books are there in each pack? And for question 4, Miss Coe bought 7 packs of books.

She bought 35 books.

How many books are there in each pack? You can pause the video here and click play when you're ready to join us.

So how did you do? Let's have a look at question 1.

Now it's very important to remember that you can only skip when you have equal groups.

So you could have skip counted B and D, and that's because B has equal groups of 5, and D has equal groups of 2.

And the equation that you should have got for B was 3 times 5 is equal to 15 because there are 3 groups of 5.

And skip counting in 5s 3 times, gives us 15.

For D, you should have got 3 times 2 is equal to 6 because there are 3 groups of 2, and our product is 6 because if we skip counted in 2s, you would've got 6.

Now for question 2, this is what you should have got.

So Jacob bought 12 packs of books.

That's one of our factors because we know that there are 12 packs, and then he bought 24 books altogether.

So that's our product.

Now, in order to work out the missing factor, we could have trialled skip counting in 2s.

And from skip counting in 2s you would've realised that there are 2 books in each pack because 12 groups of 2 is 24.

For question 3, 5 groups of 10 is equal to 50.

So there are 10 books in each pack because 5 groups of 10 is 50.

And lastly, Miss Coe bought 7 packs of books.

So 7 is one of our factors.

She bought 35 books altogether.

So 35 would've been our product.

In this case we were also calculating what the missing factor is.

So in order to do that you could have skip counted in 5s to 35, and you would've realised that there are 5 books in each pack, because 7 groups of 5 is 35.

Well done if you managed to get all of those questions correct, I'm super-proud of you.

We've made it to the end of our lesson.

Let's summarise our learning.

So today you used knowledge of multiplication to solve problems. You can now identify the group size and the number of groups in the problem.

You also know that by identifying the factors, you can calculate the product.

You can also skip count in the group size to calculate the product.

Thank you so much for joining me and I look forward to seeing you in the next lesson.

Bye.