# Lesson video

In progress...

Hello, my name is Mrs. Behan, and for this lesson, I will be your teacher.

In this lesson, we are going to focus on measuring time.

So not necessarily how to read time on clocks, but how to measure intervals of time.

First let's look at the lesson agenda.

We're going to begin by looking at the days of the months rhyme.

Then we will learn how to measure seconds.

After that, we will practise using a stopwatch.

And then at the end of the lesson, there will be an independent task.

And don't worry, I will go through the answers with you.

I know you'll be keen find out how you got it.

There are just two things that you will need to take part in the lesson.

Something to write with, so a pencil or pen, and something to write on.

If you don't have those things to hand, just pause the video here whilst you go and get them.

Remember, try to work somewhere quiet where you won't be disturbed.

So this is the days of the month rhyme, this is what we're going to begin with.

And in different months, there are different numbers of days.

The reason it's important to know this rhyme is so that you don't try and make a date to go out with a friend on a date that doesn't exist in our calendar.

For example, if you try and make a date to go out with a friend on the 30th of February, it will never happen because that date does not exist.

You're probably wondering why there are different numbers of days in the calendar.

Well, there's lots and lots of historical reasons.

But in February, we have one extra day every four years.

That fourth year is called a leap here.

And the reason we have that extra day in February on the Leap Year is because in every year there is actually 365 and a quarter days.

So by the time the fourth year comes around, we will have made at the time of one whole day.

So we add that on to the end of February because there are only 28 days in February.

So let's have a go at reading the rhyme together.

Thirty days have September, April, June and November.

Thirty-one the others date, except in February, twenty-eight.

But in a leap year by design, February has twenty-nine.

Something for you go away and practise.

So our focus today isn't necessarily on reading time, but it is going to be on measuring time.

So have a look at this clock, and just think what is the job of a wall clock like this? Well, the job of a wall clock like this is to measure ongoing time.

So time goes on and on and on indefinitely.

And the clock helps us to measure that time.

It tells us what time it is, what time is coming up.

Have you seen these before? These tools are called stopwatches, and I call them a tool because they do a job.

They actually measure time in races.

So if I was having a race with you and we gave ourselves one minutes to see how many star jumps we could do, we could start the timer, do our star jumps and count our star jumps, and then stop the timer, then we would be able to compare who did the most star jumps in that time.

The other way to use a stopwatch is to time how long something has taken.

So it might be that we run a race and we both set off at the same time.

That's when the stopwatch starts.

And then as soon as I finish, I start the stopwatch.

When you finish, someone else stops a different stopwatch.

And then we can compare times that way.

So this is a stopwatch that I have built into my phone.

Now most devices, so tablets, phones, etc, have built-in stopwatches these days.

So what's the difference between my stopwatch and the stopwatch that I just showed you earlier? Well, my stopwatch actually has a digital display, but it's not quite the same as a digital clock that you might have come across before.

So on my digital display, the first two digits show the minutes that have passed.

The next two digits show the seconds that have passed.

And the last two digits show the milliseconds that have passed.

They move really, really quick when you watch a timer.

So I have recorded my timer for one minute and I want you to get a sense of how that feels.

Now I am going to have to stay quiet whilst that timer is on, otherwise the video won't work properly.

But what you can do is you can practise counting to 60 as the timer is on.

So what do you think about the length of a minutes? I know for me just sitting here watching the screen, a minute feels like a very long time.

I was thinking of all the jobs and things I can get done in the space of one minute.

Okay, we're going to see how good you are at estimating the length of one minute.

And the clue is to remember that there are 60 seconds in one minute.

I'm going to show you a traffic light.

When you see this traffic light, the green lights, you will start counting.

And when you think that the one minute is up, you will stand up, okay? When the minute is actually up, the red traffic light will come up.

Okay, I can't actually be on the screen because you will be able to see by my face when a minute is up and I want you to guess.

So I'm going to turn the camera off and I'm going to start the timer and remember, as soon as you see the green traffic light's face, you will start counting.

Okay, let's try this.

If you've already stood up, there's only 40 seconds have passed, there's still some more to go.

50 seconds.

And that is a minute.

So did you wait the full minute before standing up, or were you too early? When there's only a minute to think about and when you're trying to calculate or estimate how long a minute is, it can be very, very tricky.

So don't worry if you stood up too early.

I think I would have done the same.

It feels like such long time.

Now that you've got a good sense of what a minute is, let's have a little bit of a competition.

We're going to see, both me and you, how many times you can say the word elephant in one minute.

So, oh, not in one minute, we're going to try and do it in 30 seconds, so half a minute.

So I'm going to press play on the screen.

Again, I won't be able to show my face, otherwise, the video won't work properly.

So you will have a go at saying the word elephant as many times as you can in 30 seconds.

Now a good way of recording how many times you say elephants so you don't lose track is, get your pen, get your paper and every time you say elephant, just do a little tally mark.

And by the end, you'll be able to total up how many that you've done.

Okay, so are you sure you understand what to do? Let's have a go.

So just like this, when the timer starts, you have our elephant, elephant, elephant, elephant, and tally how many times you have said elephants.

And when the timer starts, you can start.

Elephant, elephant, elephant, elephant.

So how many times did you manage to say elephants in 30 seconds? I thought that we could record our results on this table.

So I've written number of seconds up here, then my name and then you can write your name.

If you want to draw this out, then just pause the video here whilst you do it, because there are some other, we're going to have another challenge where we do it in 20 seconds and then 10 seconds too.

So I managed to say elephant 47 times in 30 seconds.

Did you manage to say it more times than me or fewer times than me? We're going to have another go this time at saying elephant in 20 seconds.

So get your pencil and paper ready again to tally up how many times you say elephant in 20 seconds.

Ready? When the timer starts you start.

So you might want to fill in your table now how many times you said elephants in 20 seconds.

I'm guessing it was less time because we have less time to be able to say elephant in.

I managed just 34 times at saying elephant.

I think are getting a bit tired as well.

So one more challenge.

How many times can you say elephant in 10 seconds? It is the last challenge now.

So 10 seconds to say elephant as many times as possible.

When the timer starts, you start.

How many times did you manage to say elephant in 10 seconds? I managed 21 times.

Did you manage more times or fewer times than me? Let's just think about the way people use the word minutes and seconds in everyday life.

Have you ever heard someone shout, "I'll do it in a minute," when they've been asked to do something? Or, "Just wait a second." Now we know that literally there are 60 seconds in one minute.

There are 60 minutes in one hour.

But when someone says I'll do it in a minute or wait a second it means they'll do it quickly because when we understand minutes and seconds, we have a sense of time that they are short time intervals.

They're not long time intervals like an hour or days or weeks.

So if someone says I'll do it in a minute, it doesn't mean they'll be doing it straightaway, but they will do it shortly.

Have a think about the different units of time measurements that we can use.

We measure time in seconds, minutes, and hours.

Read the statement on screen with me.

60 seconds in one minute.

60 minutes in one hour.

So if I was to ask you how long it took you to fly to Italy or how long it took you to walk the dog.

You would be able to say it will take me four hours or 10 minutes.

So you will be able to give me an indication of time using those words.

Here is a picture of my dog.

My dog is called Sky and she loves going out for walks just as many dogs do.

Now if I had to choose which measurement units to use or which time measurement unit to use, I would choose minutes.

And I would say I have chosen minutes to measure this because I know that her daily walks are not as long as my favourite film.

So I've chosen something else to compare it to.

So walking Sky takes me about 40 to 50 minutes while my favourite film lasts for an hour and a half.

So I know that using minutes is a better measurement unit to use.

I can be more specific if I measure in minutes.

Otherwise, I would just say less than an hour.

But that could range, if her walks are less than an hour, that could range from one minute to 59 minutes.

There are three events shown on your screen and I would like you to choose a unit of measurement of time measurement.

There are three events shown on your screen.

And I would like you to think about whether you would use seconds, minutes or hours to measure the time of each event.

The first one is flying on a holiday to Spain.

So you will say I have chosen, and then say seconds, minutes or hours, because, so then give me a reason.

The next one is writing my name in my best writing.

And how long I spend on computer games each day.

Pause the video here whilst you have a go at your task.

When you ready, come back to me and we will look at some answers together.

Okay, so the first thing to say is that everybody's answers are going to be different depending on where you might be flying from, how quickly you write or how much you love computer games.

So this is what I've written for the first one.

I have chosen hours because travelling to another country will take a long time.

I know it's not going to be quick like walking the dog in minutes, or saying elephant in 30 seconds, it's going to take me a long time.

So I do know that flying on holiday to Spain will take hours.

For writing my name in my best handwriting, I've chosen seconds because I know it doesn't take long to write my name.

We earlier felt how long a minute was, and it definitely wouldn't take a minute to write my name even if it was in my best handwriting.

And how long I spend on computer games each day.

I have chosen minutes because it will take me longer than a few seconds to play the game but not hours.