Lesson video

Hello! Welcome to today's math lesson.

You're with me, Ms. Jones.

Looking forward to get started together.

Today, we're moving on and we're looking at mass which means how heavy something is.

Sounds interesting.

Are you ready to get started? In today's lesson, we are going to compare the mass of two objects.

Now compare means, we look at two or more different things, and we see what's the same, and what's different about them.

Mass means how heavy something is, so we are going to comparing what objects that are heavy and lighter.

Let's look at our agenda.

We're going to start off by reminding ourselves what we mean by mass, then we're going to compare the mass of different objects.

You've got an independent task, and finally and end of lesson quiz to do.

You'll need a pencil and a piece of paper in order to write down your answers today, or something else to write with and write on.

You'll also need a range of objects.

These could be items from the house, such as a cup or a box, or they could be items from your toys, like a teddy bear or a doll.

If you haven't got any items just yet, you can pause the video now and go and get them, but make sure you check with your parents or carer about the objects you are getting.

Okay, go and get yourself ready and then come back.

Okay, hopefully you've got everything you need, so let's get going.

I've got two objects here that you might find in the house.

I've got a sponge, and I know my sponge isn't very heavy.

It's made out of a light material, and it's not too big.

I've also got a bottle of milk full of milk.

Mmm.

that one is a bit heavier, isn't it? Which do you think is the lightest? Can you point to it? Which do you think is the heaviest? Can you point to it? My turn, your turn.

The sponge is lighter than the milk bottle.

The milk bottle is heavier than the sponge.

Let's see what else we've got.

Oooh, here we've got a set of weighing scales.

Now these scales are a special type of scales called a balance scales.

Do you know why they call them balance scales? If we have two objects with equal mass, so they are the same weight and just as heavy as each other, these scales will balance.

If we have an object that is heavier on this side, the scales will look a little bit different.

They'll start to be unbalanced like this.

Here's my heavier object, here's my lighter object.

Have you seen one of these balance scales before at school, or in a maths lesson? Let's have a think about what that might look like.

If I put an apple on this side, and I put a button on this side, which do you think would be heavier? The apple is heavier than the button, so the scales would move down one this side, and they would move up on this side.

Which do you think is heavier: the pencil, or the apple? I think the apple is heavier.

So the apple would cause the scale to move down.

The side of the pencil would move up.

If I had two objects that were equal mass, they would stay in the middle.

This time, what do you think? Which would be heavier, the apple or the paperclip? Can you explain? I think the apple would be heavier and cause the scale to move down.

I think the paperclip would be lighter, and cause that side of the scale to move up.

Your turn to explain.

I'm going to pick two other objects to compare.

I'm going to pick the book and the pencil.

You've got a book, and a pencil.

Which object do you think would be heavier? Can you explain why? Pause the video now to try and do an explanation.

Make sure you use a full sentence.

What did you think? I think the pencil might be lighter than the book.

I know that pencils need to be light, so that I can do my work with them.

I think the book is heavier than the pencil.

This time we've got an image.

Which is heavier, the pig or the cow, and how do you know? I can see that the scales is lower on this side, which means the cow is heavier than the pig.

What could we say about the pig? Well, we could use the word lighter.

The pig is lighter than the cow.

Although the pig is quite heavy, the cow is even heavier.

What about this time? This time our scales are balanced, they're at the same height.

Just right, and balanced.

The horse says, "I am as heavy as the cow".

They have equal mass.

They are both as heavy as each other.

The cow and the horse have equal mass.

Can you say that? The cow and the horse have equal mass.

Hopefully, you had a good go at explaining.

Oooh, we've got a different image here.

We've got, the ketchup is heavier than the crayon.

If the ketchup is heavier, which side would it be on? The ketchup would be on this side, as this side is lower.

Let's look at the next one.

We can say the crayon is lighter than the ketchup.

The crayon here must be on this side, because it's higher.

The heavier object always goes on the lower side.

I'd like you to be using words like 'heavier' and 'lighter' in your task today.

Here's our images to help us.

The ketchup is on the heavier side.

The crayon is on the higher side because it's lighter.

Down here, the ketchup is on the lower side, the crayon is on the higher side.

It's time for your independent task.

Here you can see some scales.

I'd like you to find a heavy item in your house.

Not too heavy, make sure that you can lift it okay, and if you need to, check with you parent or carer.

Then, can you find something that is lighter than that? Think about where they would go on the scales.

Once you've done that, can you use your objects to complete your sentences? The hmm is heavier than the hmm.

Than can you use one using the word lighter? The hmm is lighter than the hmm.

Okay, you'll need to fill in the blanks using the objects you've chosen.

Once you're done, there's a challenge question.

Can you find two different objects in your home that you think would weigh the same? That would have the same mass, and cause the scales to be balanced.

Okay, it's time to pause the video and go and do you task.

Once you're done, come back to the video to finish off.

Hopefully, you've had a chance to have a go at today's task.

You've worked really, really hard today.

If you want to, you can ask your parents or your carer to share your work with Oak National.

Now it's time to go and do your multiple-choice quiz.

Thanks everyone, good work today!.