Lesson video

Hi, everyone, my name is Miss Sabzvari and I'm really excited that you decided to join me today for our maths lesson.

The unit we're studying is multiplication and division.

In the previous lesson, we calculated the multiplication table of two, by skip counting.

In this lesson, we will focus on solving multiplication word problems. So, when you're ready, let's begin.

Let's have a look at today's lesson agenda.

First, we'll begin by looking at bar modelling for multiplication word problems. Then, we'll move on to our talk task.

Next, we'll be solving multiplication problems and finally, you will complete your independent task.

Before we begin today's lesson, you will need the following items. You will need something to write with and something to write on, you will need some cubes or counters, alternatively, you can ask your parents or carer to cut out some small pieces of paper that you can use instead, and finally, you will need a ruler.

So, please pause the video now to get the items that you need.

Bar modelling for multiplication word problems. Let's read the word problem together, follow with me.

The school cook is serving broccoli.

She puts two pieces of broccoli on each child's plate.

How many pieces of broccoli will there be on five plates? I would like you to pause the video now and tell your screen what is known and what is unknown.

Great work, so we know how many groups there are, so we know that there are five plates and we know how many pieces of broccoli are in each group.

Okay, so we know the value of each group.

So, can you now represent this word problem using a bar model? Have a go.

So, your bar model would look something like this.

We know that there are one, two, three, four, five groups or five plates, so we will split our bar model into five, and we know the value of each group is two, so five groups of two.

Pause the screen now and write down the multiplication equation for this problem.

Great work, so we know that five groups of two is equal to 10.

Let's have a look at the next word problem.

Follow with me.

The school cook is making cakes.

Each cake needs two eggs.

The cook is making six cakes.

How many eggs does she need? Again, pause the video here and tell your screen what is known and what is unknown.

Great work, so we know that the cook is making six cakes, so we know that there are six equal groups, or six equal parts and we know that in each part, there are two eggs.

So, pause the video now and create your bar model and write down the multiplication equation.

Great work, so your bar model will look something like this.

Your bar model would be split into six equal parts and each part has a value of two.

Make sure that you clearly label your parts, okay, that's really important.

And your multiplication equation would be six groups of two equals to 12.

Great work, well done, everyone.

Now, moving on to your talk task.

What I would like you to do is to read the problem and I would like you to create a bar model to find the calculation needed to solve the problem and finally, I would like you to solve the problem.

Okay, so I'm going to read the questions for you and then you can complete your work.

Each child needs two pieces of cutlery, a knife and a fork.

There are three children.

How many pieces of cutlery are there altogether? And the next question is, each class gets three oranges in their fruit box each day.

How many oranges would two classes get? So, let's have a look at our answers.

For the first question, we know that there are three children, so I know that on my bar model is going to be split into three equal parts.

And I know that each part has the value of two, so in order for me to find the whole, I know that three groups of two is equal to six.

If you got that correct, well done.

And our next question, we know that each class gets three oranges, so we know the value of each group is three, okay.

And we want to know how many two classes would get, so we want to know what the value of two classes would be all together.

So, I know that my bar model is going to be split into two equal groups and in each group is going to have the value of three.

So, two groups of three is equal to six.

Well done.

Solving multiplication problems. Let's read the problem together.

Each child gets two carrots at lunchtime.

If there are 10 children, how many carrots are needed? Okay, pause the video now and tell your screen what is known and what is unknown.

Great work.

So, we know the value of each group and we know how many groups there are, so we know that there are 10 children and we know that each child is getting two carrots.

So, draw your bar model and complete the multiplication equation and then we will go through the answers together.

So, I know that each child is going to get two carrots at lunchtime and I want to know how many carrots are needed if there are 10 children.

So, the first thing I'm going to do is I'm going to draw my bar model, using my ruler and then I'm going to section my bar model into 10 equal parts.

Once I have done that, then I'm going to label what is known and what is unknown on my bar model.

So, I know that the value of each part is going to be two.

Okay, I'm just going to directly write the numbers in, instead of drawing the pictures.

And I know that the value of the whole is unknown, okay, so we're trying to work that out, but I know that there are 10 parts, so 10 multiplied by two is equal to 20.

So, I know that my whole is 20.

Let's have a look at the next word problem.

Follow with me.

Each child get 10 carrots at lunchtime.

If there are two children, how many carrots are needed? Okay, again, I would like you to pause the video now and to tell your screen what is known and what is unknown.

Then I would like you to draw your bar model and finally I would like you to complete your multiplication equation.

I know that there are two children, so I know that my bar model needs to be split into two, okay, into two equal parts.

And each child gets 10 carrots, so the value of each part is 10.

I'm going to label what I know and I want to know how many carrots are needed altogether.

So, the value of my whole is unknown.

Two groups of 10 is equal to 20, so I will need 20 carrots altogether.

So, let's have a look at the two bar models for the two word problems, that we've just completed together.

What I would like you to do is to pause the video and to answer the following question.

What's the same and what's different? Do that now.

So, what you might have noticed is that the whole for both of these bar models is 20, okay.

But the difference is how many parts there are and the value of each part.

So, on the first bar model, there are two parts and each part has a value of 10, so two multiplied by 10 is equal to 20.

And our second bar model, we can see that there are one, two, three, four, five, six, seven, eight, nine, 10 parts with the value of two.

So, we know that 10 multiplied by two is equal to 20.

And now it's time for you to complete your independent task.

What I would like you to do is to solve the word problems using bar modelling, okay, so I'm going to read the questions for you and then I would like you to draw your bar model and to write down your multiplication equation.

Then, we will go through the answers together.

So, the first question, there are two tables full in the lunch hall.

If four children sit on a table, how many children are there altogether? And the next question, bananas come in bunches of two.

There are four bunches of bananas in the lunch hall.

How many bananas are there in total? Okay, so let's have a look at the answers together.

We know that there are two tables full in the lunch hall, okay, so we know that there are two parts and the value of each part is four, that's because four children can fit around one table.

So, my bar model is going to be split into two and the value of each part is going to be four.

So, two groups of four is equal to eight.

So, eight children can fit round the two tables.

And looking at the second question, we know that the bananas come in bunches of two, okay, so we knew the value of one section is going to be two.

We know that there are four groups, okay, so my bar model is going to be split into four equal groups and the value of each part is going to be two.

So, one, two, three, four groups of two or four multiplied by two is equal to eight.

If you'd like to, please ask your parents or carer to share your work on Twitter, tagging @OakNational and Learn With Oak.

And now, it's time to complete your end of lesson quiz, bye!.