Lesson video

Hello, I'm Miss Mia 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'll be able to explain and represent multiplication when a group contains zero or one item.

Your keywords are on the screen now and I'd like you to repeat them after me.

Zero, group, grouping.

Fantastic.

Let's move on.

Now, this lesson is all about explaining and representing multiplication when a group contains zero or one items. So, there are two lesson cycles in this lesson.

The first lesson cycle is all to do with having a group size of zero, and then we move on to looking at a group size of one.

You'll meet Alex and Jacob to help us with our mathematical thinking throughout this lesson.

Let's begin.

Ooh, "It's my birthday" shouts Alex, Anheap says "The desserts have been arranged into groups".

Now I have to let you into a little secret here.

Somebody's been feeling a little bit hungry and they've been up to no good.

Let's find out why and what's happened.

So, it's Alex's birthday.

His mom has arranged cupcakes on a plate.

Now we can see that there are two groups of three cupcakes.

You can write this as three plus three, so that's repeated addition.

So you can also write this as two times three.

However, someone at the party sneakily ate them all.

Oh dear.

Right, so here we are.

There are two groups of zero cupcakes.

So you can write this as zero plus zero, so that's our repeated addition.

You can write this as two times zero.

I wonder who ate those cupcakes? Now milkshakes have also been prepared for the party.

So we can see that there are two groups of four milkshakes.

You can write this as four plus four, and that's our repeated addition expression there.

You can also write this as two times four.

So that's our multiplication equation.

However, someone at the party has already drank them all.

Oh my goodness.

So now, there are two groups of zero milkshakes, so two plates with nothing on them.

You can write this as zero plus zero, which is our repeated addition expression.

Or you can write this as a multiplication.

So that's two times zero.

Oh, I wonder who's drank all the milkshake.

Now Jacob tells Alex what has happened.

"I can see two plates left".

"There are two plates, but there are no milkshakes".

Oh dear.

So there are two groups of zero milkshakes.

You can write this as zero plus zero.

So that's our repeated addition expression.

You can write this as two times zero.

Ultimately, there's nothing there.

Over to you.

Look at the representation below.

There are four empty plates.

Select the correct multiplication expression for this.

So A is three times zero, B is four times zero, and C is five times zero.

You can pause the video here.

So how did you do? Someone has eaten all the other desserts that were placed on the plate.

Hmm.

What did you guys get? Well, there were four groups of zero because there were four empty plates.

Well, Alex's mom noticed that the plates were becoming empty, so she organised more plates of cupcakes.

You can write this as three plus three plus three plus three.

There are four groups of three cupcakes.

So there's our repeated addition there.

You can also write this as four times three.

However, someone has come along and eaten them all again.

Oh my goodness.

And now we're left with four empty plates.

So there are four groups of zero cupcakes.

I wonder who's going around eating everything? Goodness me.

So you can write this as zero plus zero plus zero plus zero.

So that's our repeated addition expression.

You can write this as four times zero.

Wow.

Right? So have a look.

These are empty cupcake stands.

Surely it must be more than one person sneakily eating everything.

There are six empty cupcake stands.

Select the correct multiplication expression for this.

Is it A, four times zero? Is it B, five times zero or C, six times zero? You could pause the video here.

So what did you get? If you got six times zero, you are correct because there are six empty cupcake stands, which means there are six groups of zero.

Right, onto the main task for this lesson.

And I promise you I will reveal who it was that ate all the desserts during the party.

So question one, draw lines connecting each picture of cupcakes with the correct multiplication expression.

So for the first picture, you've got three plates with three cupcakes.

Then you've got three empty plates with zero cupcakes.

Then you've got three plates with two cupcakes in each.

And for the last one you've got three plates with one cupcake each.

And you'll be matching this to the multiplication equations three times one, three times two, three times three, and three times zero.

For question two, you are going to complete the expressions to describe the sandwiches on the plates.

So for the first example, you've got two plates with one sandwich, and then you've got two empty plates.

Then for the second example, you've got four plates with three sandwiches, and then you've got four plates with zero sandwiches.

And lastly you've got five plates with four sandwiches and then five empty plates.

So you can pause the video here.

Off you go.

Good luck.

So how did you do? This is what you should have got.

For the first picture, we can see three plates with three cupcakes.

So that's the same as saying three times three.

For the second image, we've got three empty plates.

So that's the same as saying three times zero.

There is nothing on that plate.

For the next image, we've got three plates with two cupcakes each.

That's the same as saying three times two.

And lastly, we've got three plates with one cupcake each, that's three times one.

Well done if you managed to match the images to the correct multiplication expressions.

For question two, this is what you should have got.

So for the first equation, we've got two plates with one sandwich each.

This can be represented as two times one.

And then our two plates are empty, so because there's nothing on there, we can represent that with zero, because zero means nothing.

So two times zero.

For the second set of plates, we've got four plates with three sandwiches.

So that's the same as saying four times three.

And then the plates are emptied.

So the amount of plates are the same, so that's four.

However, there's nothing on there.

So we are multiplying that by zero.

So you should have got four times zero.

And lastly, we've got five plates all together.

So five would've been one of the numbers in our multiplication equation.

And then we've got four sandwiches on each plate.

So that's five times four, and then the plates are emptied.

So whoever's been sneakily eating everything has done a really good job there.

So now we've got five plates that are empty.

So that's the same as saying five times zero.

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

And I'm now going to reveal who ate all of the desserts and sandwiches.

It was Jacob himself.

He ate all the sandwiches, so he tricked poor Alex.

Well done for making it to the end of this lesson cycle, let's move on.

Right, now we're going to look at group size of one.

Let's begin.

Now Ms. Coe is arranging some flowers.

Each vase has three flowers.

There are two groups of three flowers.

You can write this as three plus three, and that's our repeated addition expression.

You can also write this as two times three, and that's because there are two groups of three and we've added three two times.

Now Ms Coe gives some flowers away.

Ooh.

Okay, now each vase has one flower.

There are two groups of one flower.

You can write this as one plus one.

So that's our repeated addition expression there.

That's one way to represent that.

We can also write this as two times one.

So that's another way to represent what we can see in that image, using multiplication.

Later, Ms Coe arranges more flowers for her friends party.

Jacob says, each vase has four flowers now and there are four vases altogether.

So there are four groups of four flowers.

You can write this as four plus four plus four plus four, and that's our repeated addition expression there.

You can write this as four times four.

This time, she spots that some of the flowers are wilting.

She throws some away.

Ooh.

Okay.

There are four groups of one flower each.

You can write this as one plus one plus one plus one.

You can also write this as four times one.

Jacob makes an observation.

He says he can see four flowers.

Is Jacob correct? What do you think? Now Alex says there are four vases and one flower in each vase.

So rather than looking at the whole image together, we are looking at each vase separately.

So there are four vases and one flower in each vase.

So there are four groups of one flower.

You can write this as one plus one plus one plus one.

And you can also represent this using a multiplication expression.

So that is the same as saying four times one.

There we are.

Over to you.

So I want you to look at the representation below.

There are six vases, and I'd like you to select the correct multiplication expression for this.

So is it A, six times zero, B, six times one, or C, six times two? You can pause the video here and click play when you're ready to rejoin us.

So what did you get? Well, You should have ticked B, six times one.

And that's because there are six groups of one, six vases with one flower each.

Now Alex is representing groups of one in a maths lesson.

Let's look right at the middle.

We've got the expression, five times one.

Now to the top left, he's written a sentence there.

So there are five groups of one.

Then for the repeated addition expression there, he's got one plus one plus one plus one plus one.

Then he's represented five times one as a bar model.

And lastly, he's got a drawing as well.

So I want you to think about what is the same and what is different.

Have a think.

Well, the drawing shows five groups of one dot each.

The bar model shows five bars representing one each.

The repeated addition expression shows five ones.

And when it comes to the sentence, we are saying that there's five groups of one.

The difference is that the representations look different.

So they're all showing five times one, but they all look different.

Over to you.

So Alex has represented groups of one using a bar model.

Use this to write down the multiplication expression.

Have a look at how many bars there are and what the value of each bar is.

You can pause the video here.

So how did you do? Well, there are six bars.

Each bar represents one each.

So your multiplication expression would've been six times one.

Now we're going to start our main task for this lesson.

So for question one, Alex started to draw some equal groups, complete his drawing.

I have seven times one, then I have something times one, and then lastly, I have something multiplied by something.

So what you could do is, if I were you, I would start off by seeing how many groups there are and then how many items or dots you need to draw in each group.

For question two, I'd like you to complete the model using your knowledge of multiplication and grouping.

So if I were you, I would start off by looking at the multiplication expression in the middle and then representing that as a sentence and then going on to repeated addition, followed by drawing a bar model and then a drawing.

So think about what the four represents and what the one represents in the expression.

You can pause the video here.

Good luck.

Off you go.

So how did you do? Well for question one, this is what you should have got.

So let's look at this in a little bit more detail.

So when looking at seven times one, what does the seven represent? Well, the seven represents the number of groups.

So we needed to draw seven circles, and the one represents the number of dots in each group.

So we would've drawn one dot in each group, and you should have ended up with seven circles with one dot in each.

This shows seven times one.

Then for six times one, we knew that there was one dot in each group, but there were six circles, so we needed to draw six circles altogether to show six times one.

And lastly, we knew that there were five groups, so that is five.

And then the one represented how many dots there were in each group.

So that would've been five times one.

For question two, let's begin with the sentence then.

So four times one is the same saying there are four groups of one.

Four groups of one can be also represented as one plus one plus one plus one.

So adding one four times.

The bar model would've showed four bars, each representing one.

And lastly, for the drawing, we would've had four groups with one dot inside each group.

This would've shown four times one.

If you managed to get all of those correct, really well done, because you've shown that you know what the numbers in the multiplication expression represent, and to represent this accurately when the group size is one.

Fantastic.

You've made it to the end of this lesson.

Well done.

I'm really proud of you.

So in this lesson, you learn how to explain and represent multiplication when a group contains zero or one items. You should now hopefully understand that you can explain and represent multiplication when a group contains zero or one items. You should also understand that the group size can be one and the number of groups can be one, and that groups of zero can be written as an addition and multiplication expressions.

So hopefully now you understand the difference between groups containing zero or one items. I look forward to seeing you in the next lesson.

Thank you so much for joining me, see you in the next one.

Bye.