# Lesson video

In progress...

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

In this lesson, we are going to transport ourselves to a television studio.

We now work behind the scenes making sure that the best programmes start and finish at the right times.

We wouldn't want our viewers to miss out on the favourite programmes now, would we? So, if you're ready, let's check out those times.

We're going to start by looking at the lesson agenda.

We're going to use a timeline to begin with to look at time intervals.

Then we will compare lengths of intervals.

After that you will practise calculating time intervals and at the end of the lesson, there will be an independent task for you to have a go at.

I know you'll be keen to find out how you got on, so I will go through the answers with you.

There are just a couple of things you will need for this lesson.

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

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

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

So to get our brains nice and warmed up ready for maths, I have a spot the mistake activity for you.

I'm going to show you some options on screen and you need to work out which one is incorrect.

So the statement is 1272 is the same as-- Here are your options.

Now a suggestion I might make, is to help you, you might want to draw out your base 10 pieces or your Deans.

Or if not, if you've got some pasta in the kitchen, dried pasta makes very good representations of Deans.

So I've used a ball of tagliatelle here for 1000.

I've used 10 spaghetti sticks to represent 100, one stick of spaghetti to represent the 10, and one piece of twisty diffusely dry pasta to represent a one, so if you want to get creative and little bit hands on then you can certainly represent 1272 using the pasta pieces from the kitchen.

If not, don't worry, like I said, you may want to draw them out.

So, pause the video here, whilst you try and spot the mistake.

Okay, did you manage to spot the mistake? The mistake was this statement, one thousand, two hundreds seventeen tens and two ones.

So if you represented your base 10 with drawings or pasta, you will have worked out why the mistake lies in that seventeen tens.

So, if we write it out in numbers, we have 1000 plus 200 plus 170 plus two ones.

All of that recombined makes a total of 1372.

Well, and if you manage to spot the mistake.

So I have to say, congratulations on your new job.

How amazing is that that you've been hired by a television studio.

So, your job now is to start putting out the best TV programmes out on air.

So, you will need to put something together like this.

This is called a TV schedule.

So, you'll need to calculate how long the programmes are going to be on air for.

So, we use the start and finish times to do this.

So, "Bogus the Fungusman" starts at 10 minutes past seven, and it finishes when "Nico the Naughty" begins at 25 minutes past seven.

Now I know that you can work out intervals of time on an analogue clock.

But as you notice, these are all in a digital format.

When we read time on an analogue clock, we can unravel the scale that shows us the minutes like this here.

So we can use this scale and this example, to help us understand digital time.

So, here is a timeline.

So you can see I've put start times here seven o'clock, then an hour later it will be eight o'clock and an hour after that it will be nine o'clock.

And our job is to work out the length of the first programme.

To do this, let's just mark in, what would be at these halfway points.

What time would be halfway between seven o'clock and eight o'clock? That's right, half past seven would be halfway between and halfway between eight o'clock and nine o'clock is half past eight.

The first programme to go on air is "Bogus the Fungusman." Sounds like a very exciting programme.

So tell me the time it starts.

That's right, 7:10 or 10 minutes past seven.

Where do you think that would go on our timeline if we had to plot out 10 minutes past seven, where would you put it? Somewhere around about here? Okay, so the end point is when "Nico the Naughty" starts at 25 past seven.

Just have a thing use your finger on the screen.

To estimate were 25 past seven would be round about here? I estimate that 25 past seven would be round about here because I know that this pink marker here shows me half past seven.

So, 25 minutes past seven is not as far away around the clock has half past seven.

So, I'll put it here.

So, we now need to work out the gap between these two times.

And this is the time interval.

That is our unknown.

So, how will we work it out? Well, I've put an analogue clock over here just to help us the start time is 10 minutes past seven, and the end time is 25 minutes past seven.

So, how can we work out to go from 10 past to 25 past? Maybe you're counting fives, five minutes past 10 minutes past 15 minutes past so 15 minutes have passed since 7:10 till 7:25, we now know that "Bogus the Fungusman" is a 15 minute programme.

Let's have a look at "Nico the Naughty".

Can you work out on the timeline where 25 past seven would be? Here we notice that because that's where we put the end of "Bogus the Fungusman" right then, so we now need to work out when the end time is of "Nico the Naughty".

So, let's look at the time schedule.

The end time is 7:40, use your finger on the screen to find out to estimate where 7:40 might go.

I put the arrow here, because 7:45 would be in between 7:30 and eight o'clock.

So, that would be halfway.

So, I put it just below, so 7:40 I've estimated would go around here.

So, we now need to find out the gap between our first and our second arrow.

How will we work it out? Well, I've put it an analogue clock in the corner here, so you can see at the side.

So, the start time is 25 past seven, and the end time is 20 to eight.

So, we need to work out that distance there.

That's the time interval.

Now there are different strategies, you can count on an analogue clock, but you might not always have an analogue clock available.

So, I can use my understanding of number to help me, 25 past until half past would be five minutes and then from half past or 7:30 till 7:40, would be 10 minutes.

So, if I add my five with my 10 that tells me 15 minutes.

So, I now know that "Nico the naughty" is a 15 minute programme.

You're doing such a good job, at your new job, I'm glad you've been hired.

So, where would 7:45 go on the timeline? I mentioned this one earlier.

That's right, it would go halfway between 7:30 and eight o'clock.

So where's the ends time going to go? That's right over here, now then we've past the hour with "Terrible Topics" we've gone past eight o'clock.

Is that going to confuse as when working out the time? I'm sure not.

So, we need to find out the gap between the two time, the interval.

So, here is an analogue clock to help you and watch the time change.

Okay then, so now it shows quarter past eight.

I'll go back so quarter to eight.

quarter past eight, how much time has passed? We've seen that half an hour has passed.

So, we know "Terrible Topics" is a 30 minute programme.

I could have used my understanding here that quarter to eight is 15 minutes away from eight o'clock and from eight o'clock till quarter past eight that's another 15 minutes two 15s make 30.

Time now for you to have a go.

I'd like you to work out the length of "Newzbeatz".

How long does this programme last? You have all the information you need on the screen.

So, just pause the video whilst you do it.

Okay, then so job number one, I hope you managed to put the arrow for the start time of "Newzbeatz", which is quarter past eight.

Then we put on the end points, which was 8:25.

We then had to work out the distance between the two and that will tell us the time.

What was that word? Interval, that's right the time interval.

So how long has passed between quarter past eight and 25 past eight, 10 minutes.

So, we know that "Newzbeatz" is a 10 minute programme.

Great work.

Congratulations again, because you did such a good job working for the television studio.

You have now been employed by the New Town Cinema.

Cinemas play programmes that are longer.

Here are the showing times for the film's, what is going to help me, work out the length of each film? That's right, we can use a timeline.

We've been tasked with the job of finding out the length of the film called "Mermaids".

So, let's begin by putting the information we know onto a timeline.

So we're going to look at "Mermaids" and the first job is to look at the start and end times.

Well, from the show poster, I know that the start time was 2:55 p.

m.

and the end time is 4:20 p.

m.

Once we've done that, it's important we put the o'clock times in between and this is so that we can work out the intervals in smaller sections, makes it easy for us to calculate the duration of the whole film.

So, our first job is to work out the interval between five to three and three o'clock which is five minutes.

We then need to work out the distance between three o'clock and four o'clock which is lovely and easy, it is one hour.

What's the time between four o'clock and 4:20? Exactly 20 minutes.

Let's combine these times now because really what we've done is we've partitioned the time into smaller chunks.

One hour plus 20 minutes plus five minutes gives us a total time of one hour and 25 minutes.

So, "Mermaids" is one hour and 25 minutes long.

Now, we are going to work out the length of the film "Land of the Dragons".

So, make a note of the start time and the finish time.

What do you think we should draw out to help us first? That's right, let's draw a timeline.

Can you remember what we need to put on it first? We need to put on the start and the end times, I hope you've made a note.

The start time was 4:20 p.

m.

and the end time was 6:05 p.

m.

What was the next step? We need to put the o'clock times in between.

And again, this breaks down that really long length of time into smaller chunks, which is easier for us to calculate the time interval.

So, let's find the distance between 20 minutes past four and five o'clock.

Do you know what that is? Well, it is 40 minutes.

If I imagine that five o'clock is a whole 60 minutes has passed into the hour, I can actually do 60, subtract 20 and I know that the gap is 40.

So, there's a little tip for you.

We now need to work out the interval between 5 p.

m.

and 6 p.

m.

Nice and easy it is one hour and then from 6 p.

m.

to 6:05 is just five minutes.

Can you combine that total there and we'll see how long the film is.

One hour plus 40 minutes plus five minutes is equal to one hour and 45 minutes.

So, "Land of the Dragons" is one hour and 45 minutes long.

We now can compare the film's, we can see which one is shorter and which one is longer.

So, which is the longer film between "Mermaids" and "Land of the Dragons"? That's right "Land of the Dragons".

It is actually how many minutes longer? Its 20 minutes longer than "Mermaids".

I'd like to work out the lengths of the films and then compare them.

Once you've done that, complete the table.

So, you're going to show me the film and the length in hours and minutes.

And then when you've worked out both, in here write the name of the film that is longer.

For this one, workout the length of the two films and work out which one is shorter.

When you ready, come back and we'll go through the answers together.

The length of "The lion Princess" film, was one hour and 25 minutes.

And "Back to Wizardland" was one hour and 45 minutes.

The longer firm was "Back to Wizardland".

How did you get on with "Space Attack" and "The Fire"? "Space Attack" was a very long film, two hours and 15 minutes.

And "The Fire" was just one hour and 15 minutes.

You were asked which film was shorter? Well, the answer is "The Fire" is the shorter film.

Just before we finish the lesson, I want to show you how I came to those times.

So, the first thing with "The Lion Princess" is I drew a time line, the start time was 4:45.

The end time was 6:10.

And I marked on five o'clock and six o'clock in between and then worked out that there was 15 minutes between 4:45 and five o'clock, one hour between five and six o'clock and just 10 minutes between six and 10 past six.

I combined that together to work out that "The Lion Princess" was one hour and 25 minutes long.

I then took "Back to Wizardland".

And I think there is two ways, and I wanted to show you both ways.

This was the first way.

So, using our strategy, I put the start time on first at 10 minutes past six, and then the end time which was 7:55.

I marked on the hour in between, which was seven o'clock, I worked out the difference between or the distance in time, between 10 past six and seven o'clock which is 50 minutes.

And then from seven till 7:55.

The time was 55 minutes.

So I had to combine those together.

So, 55 plus 50 minutes was equal to 105 minutes.

Now you'll notice I've subtracted 60 here, and this is to help me work out the time in hours and minutes.

There are 60 minutes in an hour.

So, if I take 60 away from 105 is like I'm taking away one hour's worth of minutes, that left me with 45.

So I know that the time was one hour and 45 minutes long.

So, I thought, how can I work out another strategy which made it a little bit easier? So, this is what I did.

I put my start time and end time on as I did before, and I put the old clock time in the middle.

But then I knew that it was going to be longer than an hour.

So I jumped from 6:10 to 7:10.

And I knew that was an hour.

Then I worked out 7:10 till 7:55, which I worked out was 45 minutes.

Again, combine those together and know that the film length was one hour and 45 minutes.

Which method would you have chosen? I actually think the second method is more efficient, but you have to be confident with numbers and times to be able to do that method.

I looked at "Space Attack" a longer film.

We started at five, sorry, five minutes to eight and then it ended at 10:10.

There were actually three hours for me to write down in between here three o'clock, eight o'clock, nine o'clock and 10 o'clock.

But I did my usual method, my usual strategy of finding out the distance in between each time.

So five minutes plus an hour, plus an hour, plus 10 minutes, combined all together and it was two hours and 15 minutes.

I then looked at "The Fire" and I use that second strategy that I've used earlier.

I knew that I could go from 10:10 to 11:10 and it would be an hour long.

Then I go from 11:10 to 11:25.

The distance there is 15 minutes, so the total time of the film is one hour and 15 minutes.