Lesson video

Hello everybody.

My name is Mrs. Johnson.

I am so excited to be here today to help you with some of your maths learning.

I hope you're ready to work hard and have lots of fun.

Let's have a look at what we're going to be learning about today.

This lesson is called, "Estimate and Measure Length and Record Results in a Table".

It comes from the unit number zero to 20 in different contexts.

By the end of this lesson you will be able to estimate length, use a ruler to check your estimates, and record these in a table.

That sounds like lots to do in one lesson but I know that you will be able to do it, and we'll work hard together.

There are some important keywords that you need for this lesson.

We are going to practise those now.

It will be my turn first and then your turn to say each word.

Ready? My turn, estimate.

Your turn.

My turn, measurement.

Your turn.

My turn, table.

Your turn.

Well done.

One of these words you might sometimes hear in a slightly different way.

We said estimate the first time, but sometimes you might also say estimate.

Let's practise that one now.

My turn, estimate.

Your turn.

Well done.

There are going to be two parts to this lesson today.

To begin with, you are going to learn how you can record results in a table, and then in a little while you are going to learn about using a table to find information.

Let's start with learning about recording results in a table.

There are two friends in this lesson who are going to help you today, their names are Sophia and Jun.

Listen really carefully when they tell you things, because they have lots of helpful information that will help you with your learning today.

Sophia and Jun went for a walk and they collected some items. I wonder if you've ever done that.

It's really nice when you can go out for a walk and collect lots of different things to bring back with you.

Sophia is going to estimate the length of some of these items. First, she's going to have a think about this leaf.

She's going to use a 10 centimetre strip of paper to help her estimate the length.

I think Sophia has noticed something about this leaf and this strip of paper.

I wonder if you've noticed it too.

Sophia says, "My estimate for the length of this leaf is about 10 centimetres, because the leaf is the same length as the strip of paper." If they are the same length and we know the strip of paper is about 10 centimetres long, the leaf must be about 10 centimetres long too.

Now she's going to try a different leaf.

She needs her 10 centimetre strip of paper again, this time, have you noticed? Sophia has noticed that it's a little bit shorter than the 10 centimetre strip.

Sophia says, "My estimate for the length of this leaf is about nine centimetres because it is close to 10." That sounds like a sensible estimate, doesn't it? If you don't agree and you would give a slightly different estimate, that is okay.

We're going to talk more about that in a little while but remember that an estimate is a sensible guess, so not everybody will think of the same sensible guess and that is okay.

Now Sophia wants to estimate the length of this feather.

Do you notice anything about the feather and the strip of paper? Sophia has noticed that the feather is longer than the 10 centimetre strip, so she says, "I can't estimate its length." She thinks she won't be able to do it because the feather is too long.

What do you think? I bet you can think of a solution to this problem.

Sophia could use two strips of paper to help her to estimate longer items. Let's give Sophia another strip of paper.

Now that she has two 10 centimetre strips, she could estimate items that are up to 20 centimetres long because 10 plus 10 is equal to 20.

How is she going to estimate the length of this feather? She's noticed that the feather is only a little bit longer than 10 centimetres, so Sophia says, "I estimate that it is 12 centimetres long." Again, like we said last time, if you have a slightly different estimate, that is okay.

It's just a sensible guess to say, "I think it is about this many centimetres long." We don't all have to think of exactly the same estimate.

Now Sophia wants to estimate the length of this stick.

She says, "I can see this is 10 and a bit.

My estimate for the length of this stick is about 14 centimetres because 10 plus four is equal to 14." So Sophia has noticed that this stick has gone past the 10 and she thinks the bit past the 10 looks like about four.

She knows 10 plus four is 14 so her estimate is 14 centimetres this time.

Let's check if you can estimate length.

How would you estimate the length of this stick? Look carefully at the 10 centimetre strips and have a think.

Pause video and decide on your estimate.

Well done.

Let's see if you are thinking in a similar way to Sophia.

Sophia says that, "This stick is very close to 20, so my estimate for the length of this stick is about 19 centimetres because 19 is one less than 20." She's used her knowledge of a number line.

She knows that 19 comes before 20 so her estimate is 19 centimetres long, and Sophia is going to record her results in a table.

Which parts of the table will Sophia be completing? I can see the headings object, estimate, and measurement.

Sophia has been estimating the length so she is going to complete the object and the estimate part of the table.

Sophia doesn't have any measurements so she's not going to write anything in the measurement part.

This was Sophia's first estimate.

Sophia estimated that the orange leaf was about 10 centimetres long, so in the object part she's going to write orange leaf and in the estimate part she can write 10 centimetres.

Now she's recorded her first result.

Her second estimate was this leaf.

Sophia estimated that this leaf was about nine centimetres long, so in the object Sophia can write brown leaf and in the estimate, Sophia can write nine centimetres.

Let's check if you know how to put results into a table.

Could you help Sophia to record the last two results into this table? You need to look carefully at the pictures and decide what information you would write into the table.

Pause the video and have a go at that now.

Okay, let's see what you would write in this table.

Let's see if Sophia agrees with you.

Sophia would write feather in the object and 12 centimetres in the estimate.

If you gave a different estimate that is close to 12 centimetres, that is okay.

For the second result, Sophia would write stick and she would write 19 centimetres as her estimate.

Sophia has finished recording all her results in the table but she's noticed something.

The table doesn't look complete, it's still got empty parts.

What could we do next? Have you got any ideas? Jun has an idea.

Jun says, "I will measure each item with a ruler, then I can complete the measurement part of the table." Jun's going to use a ruler to get a measurement for each object.

First, he's going to get a ruler and he's going to measure the length of this orange leaf.

He's going to place the ruler and make sure that the zero on the ruler lines up with the start of the leaf, and he can see that this leaf is 10 centimetres long.

He's going to add that measurement to the table, the orange leaf is 10 centimetres long.

He's going to find where it says orange leaf, in the measurement part of the table he can now write 10 centimetres.

Do you notice anything about the estimate and the measurement for the orange leaf? Jun has noticed that the estimate and the measurement are both the same, they are both 10 centimetres.

I wonder if that's going to happen for all the objects.

Let's have a look.

Next, Jun's going to use a ruler to find a measurement for the brown leaf.

Again, he has made sure that the leaf is lined up with the zero on the ruler, and this time he can see that the brown leaf is eight centimetres long, so he's going to add that measurement to the table.

The brown leaf is eight centimetres long.

Oh, what do you notice about the estimate and the measurement this time? Jun says, "The estimate and the measurement are different this time." Sophia says, "That is okay, my estimate was a sensible guess.

Your measurement is more accurate." Sophia is reminding us that sometimes the estimate won't be exactly the same as the measurement, and that is okay.

An estimate is just a sensible guess to say it's about this many centimetres long, but a measurement is accurate and we're saying exactly how long something is.

Can you help Jun to find the measurements for the last two objects that he needs to record in the table? Pause the video and find the measurements for these two objects.

Let's see if you have found the correct measurement.

The feather is 11 centimetres long and the stick is 19 centimetres long.

Well done if you found those measurements.

Now could you help Jun to add those measurements into the table? Pause the video again and talk about where you would write these measurements in the table.

Let's see if you are right.

The feather is 11 centimetres long, the stick is 19 centimetres long.

Did you notice that the measurements and the estimate for the stick were the same, but the measurement and the estimate for the feather were a little bit different? But, remember, Sophia said, "That is okay, an estimate is just a sensible guess and a measurement is more accurate." 11 centimetres and 12 centimetres are close, so it shows that 12 centimetres was still a good estimate because it was close to the measurement of 11 centimetres.

Now it's time for you to do some practise at estimating length.

There are four playdough snakes, look really carefully at the 10 centimetre strips of paper and have a think about how you could make an estimate for each playdough snake.

How many centimetres long do you think each snake might be? You're going to fill in your estimates in the boxes.

A is about mm centimetres long.

Make sure you make an estimate for A, B, C, and D.

Then, once you've finished estimating you are going to be like Jun, and you are going to find a measurement for each snake.

This time you need to look really carefully at the ruler to find the exact measurement.

How long is each of these playdough snakes? You've, again, make sure you've got to measure A, B, C, and D.

When you have found an estimate for all four snakes and a measurement for all four snakes, the last thing that I would like you to do is to record those results into this table.

Make sure that you fill in the estimate and the measurement for A, B, C, and D.

You can go and practise your estimating and your measuring now.

Off you go.

Well done, everybody.

Let's have a look and see how you got on with your estimating.

A sensible estimate for the first snake would be about 11 centimetres long, because it's only a little bit longer than 10.

For the second snake, 19 centimetres would be a sensible estimate because it's only a little bit shorter than 20.

For the third snake, C, you could say a sensible estimate would be about 15 centimetres long.

You might have said 14 centimetres, and that's okay too.

And for D, a sensible estimate is about 18 centimetres long.

If you look at B and then look at D, you can see that D is only a little bit shorter.

So if a sensible estimate for B is 19 centimetres, D needs to be a little bit less, and 18 is one less than 19, isn't it? So 18 centimetres would be a good estimate for D.

Now let's have a look at the measurements.

A is 11 centimetres long, B is 19 centimetres long, C is 15 centimetres long, and D is 18 centimetres long.

Well done if you could use the ruler to get accurate measurements for those four snakes.

Finally, you need to record your estimates and your measurements in this table.

Let's have a look.

For A, you might have said the estimate is 11 centimetres and the measurement is 11 centimetres.

For B, the estimate was 19 centimetres and the measurement was 19 centimetres.

For C, the estimate was 15 centimetres and the measurement was 15 centimetres.

And for D, the estimate was 18 centimetres and the measurement was 18 centimetres.

All the results in this table show that the estimate and the measurements were the same.

If your estimate was a little bit different to your measurement, that is okay, just check that it was close.

Remember earlier Sophia said that an estimate is just a sensible guess, whereas a measurement is more accurate.

So if your estimate is a little bit different to your measurement, that is okay.

Now you are going to learn about how you can use a table to find information.

Jun has made another table to share some new results that he has got.

He has some new objects; a green leaf, a twig, and a pine cone, and you can see his estimates and his measurements.

Sophia's looking really carefully, and she said, "I think you might have made a mistake." Can you see anything in Jun's table that makes you think that he might have made a mistake? Look carefully at the estimates and the measurements, see if you notice anything a little bit strange.

I this one here, the twig.

Jun's estimate was 15 centimetres long, but the measurement was six centimetres long.

That doesn't look right, does it? We said earlier that the estimate doesn't have to be exactly the same, but it should be close.

15 centimetres is not close to six centimetres.

I wonder what happened.

Let's have a look.

This is how Jun found his estimate for the length of the twig.

Jun looked at where the end of the twig was.

He said, "The end of the twig was here, so I estimate that it's 15 centimetres long." The arrow is pointing to about 15 centimetres, isn't it? What has Jun forgotten to do? I wonder if you've remembered.

I think Sophia knows, let's have a look.

Sophia says, "You should always place your object at the start of your strip to estimate." Jun's twig isn't at the start of the strip, it's somewhere in the middle.

Jun needs to move his twig here so it's at the start of the strip.

Now Jun can see 15 centimetres is not a good estimate.

Maybe it could be about seven centimetres long.

Jun could go back to his table and change that result, couldn't he? And he can give a new estimate of about seven centimetres, that would be a lot more sensible than 15 centimetres.

Have a look at another table that Jun wrote.

Do you think you can see any more mistakes that he might have made when he was estimating the length? Pause the video and look carefully for anything that you think doesn't look quite right.

What did you notice? Do you think Jun has made any mistakes with his estimating? Let's have a look.

The feather doesn't look quite right, does it? 16 centimetres is not close to seven centimetres, so I think something's gone wrong with his estimating.

The pine cone looks okay, eight centimetres and seven centimetres are close.

The brown leaf looks okay, six centimetres and five centimetres are close.

The stick, eight centimetres, 18 centimetres, they are not close, so I think that one might have been a mistake too.

Well done if you were able to notice where there might have been some mistakes in Jun's estimating.

Sophia is reminding us that the estimate and the measurement don't have to be exactly the same, but they should be close together.

If they're not close together, it shows that there might have been a mistake with the estimating.

This is Sophia's table from earlier on in the lesson, and Sophia can use these results in her table to describe and compare the length of the object she found.

She can say some sentences about the length of the object she found.

Sophia could say, "The stick was the longest object because 19 centimetres is the longest measurement in the table." You can see that here.

If 19 centimetres is the longest measurement, that means that the stick must be the longest object.

Sophia could also say, "The feather was longer than both the orange leaf and the brown leaf." If you look in the table here, these are the measurements for the orange leaf, the brown leaf, and the feather.

You can see that the feather is 11 centimetres long, and 11 centimetres is longer than 10 centimetres and eight centimetres, so Sophia is right when she says the feather was longer than both the orange leaf and the brown leaf.

Sophia could also say, "I estimated that the feather was 12 centimetres long, but the exact measurement was 11 centimetres long." Whereabout has she looked in the table to find that information? Let's have a look.

It's here, isn't it? In the same row as feather.

The feather's estimate was 12 centimetres, but the measurement was 11 centimetres.

Let's check if you can use a table to say some sentences about the results.

Could you finish this sentence? The mm was the shortest object.

And what about this one? I estimated that the mm was mm centimetres long, but the exact measurement was mm centimetres.

Pause the video and see how many different ways you could finish some of these sentences.

Well done for thinking carefully about that.

Let's have a look at what you might have said.

The brown leaf was the shortest object.

You all have to say the same for that sentence, there is only one way to complete that sentence.

The brown leaf was the shortest object.

The second sentence, you might have completed it in different ways, so here is one example.

You might have said, "I estimated that the brown leaf was nine centimetres long, but the exact measurement was eight centimetres long." You could have also said, "I estimated that the feather was 12 centimetres long, but the exact measurement was 11 centimetres long." Well done if you were able to use those sentences to describe the results in the table.

Now it's time for you to do a bit of practise.

I would like you to use the same table that you wrote earlier on in this lesson, and say as many different sentences to your partner as you can to describe and compare the length of the different playdough snakes.

You can call them A, B, C, and D.

You might be able to do this sentence, "A was that mm Snake." You might be able to say, "I estimated that B was mm centimetres long, but the exact measurement was mm centimetres." You might be able to say that C was mm than D.

You might even be able to think of some more sentences of your own.

Pause the video and go and have a go at that now.

Wow, you have been thinking really carefully about the results in your tables.

Well done.

Let's have a look at what you might have said.

You could have said, "A was the shortest snake." You might have said, "I estimated that B was 18 centimetres long, but the exact measurement was 19 centimetres." You may have said that C was shorter than D, and you could have said, "B was the longest snake." I bet you could think of even more sentences than those that you could use to describe and compare the lengths of these snakes.

Well done for thinking so carefully about that.

Now that you are at the end of the lesson, you know lots about estimating and measuring.

You know that when you estimate length, you think carefully and you make a sensible guess.

You know that if you find a measurement, you use a ruler so that your result is more accurate.

You've also learned how you can record estimates and measurements into a table, and you can use the results in the table to help you describe and compare the lengths in sentences.

Well done for all your careful thinking and your hard work today, you have done really well.

I hope that I will see you again soon for some more maths learning.

Bye, everybody.