# Lesson video

In progress...

Hi there, my name is Miss Darwish.

And for today's maths lesson, we are going to be converting between seconds, minutes, and hours.

And it's all going to be about time.

So before we get started, if you could just make sure you are sat in a nice, quiet place, ready to start the lesson.

So, our agenda for today is first of all, we're just going to be discussing time.

And then we're going to be looking at seconds, minutes, and hours.

And then we're going to be looking at easy ways of converting between all three of them.

And then at the end, there is a quiz for you to go and complete.

So for the lesson, you will need a pencil and a sheet of paper, and you might need a ruler for the activity at the end.

If you want to grab those things, we can start.

Okay, so I know that there are 24 hours in one day.

Is that right? Yeah, in one day there are 24 hours.

Some of these hours we sleep, we eat, we drink, we go to school, we play games.

We might go swimming or football.

Okay, so there are 24 hours in one day, but what about in one week? Tell me, how many hours do you think there are in one week? So there's 24 hours in one day.

What about one week? Okay, so that's easy.

If there are seven days in a week, right, then 24 hours in one day, so we want to know how many hours in seven days.

So that would just be 24 times 7.

Do you agree? So in one day there are 24 hours.

So then in seven days, we would just multiply the number of days by the number of hours in one day.

So that's one day, two days, three days.

Count with me.

Four days, five days, six days, seven days.

So 24 times 7 is 168 hours in one week.

A lot of which, personally, I probably spend a lot of those hours eating.

What about you? Okay, 168 hours in one week.

So there are 24 hours in one day, and how many hours in one week? 168.

What about how many hours in seven days? 168.

How many hours in two days? 24 add 24 is 48 hours.

Okay, good.

So there are 168 hours in one week or in seven days.

Now, I also know that there are 60 minutes in one hour.

So in one hour there are 60 minutes.

How many minutes are there in one day? So we know there are 24 hours in one day.

How many minutes are there in one day? Do you want to write something down or tell me? How many minutes do you think there are in one day? There are a lot of minutes in one day.

Shall we have a look together? Okay, so in one hour there are 60 minutes.

So when I get a question like this, even though this might be a simpler, basic question, the harder ones later on that you'll see, is that it's really easy, or for me, to write down key information out within a worded problem.

So one hour, there are 60 minutes.

So in 24 hours, why did I write at 24 hours? Because we're talking about one day.

And if I know how many minutes there are in one hour, we're going to stick to the same number of hours, okay? I can't do one daytime 60 because that would give me for one hour not one day.

So I know there are 24 hours in one day.

So that would be 24 times 60 should tell me how many minutes there are in one day.

24 times 60 is equal to 1,440.

I could do 24 times 6 and then multiply that by 10, and that will give me 1,440 minutes in one day or 1,440 minutes in 24 hours.

Okay, so let's just recap.

How many hours are there in a day? Shout it to me.

24 hours in one day, good.

And in one week, how many hours are there? 168 hours in one week.

What about if I asked you how many hours there are in one week and one day, what would you do? You would do 168 hours add 24 hours, because that will be one week and one day.

Okay, and how many minutes in one day or in 24 hours? In 24 hours or in one day there are 1,440 minutes.

Well done.

So, I'm going to ask you a few questions and I want you to say them back to me.

Okay, you ready? In one week how many hours are there? 168 hours, I want you to be nice and quick.

In two days, how many hours are there? 48 hours, well done.

What about in one week and one day? How many hours are there? 192 hours.

Hopefully you added 168 and 24.

Sophina's saying, "I know that there are 60 seconds in one minute." How many seconds are there in one minute? 60 seconds.

So we can remember it by 60 minutes in one hour, 60 seconds in one minute.

But how many seconds are there in one hour? A lot of seconds to count.

Shall we have a look? So again, do you want to write down your guess? How many seconds do you think there are in one hour? Don't work it out exactly.

Give a rough guess.

How many roughly do you think? So how many seconds might there be in one hour? Okay, I'm going to stop you there.

All right, so keep hold of that and we'll see.

Now we'll calculate it and we'll see if you were close enough.

How many seconds are there in one hour? So in one minute we said there are 60 seconds.

So in 60 minutes, can you see that on the left-hand side is my minute section.

And then on my right-hand side, I list my seconds, okay? That's why I didn't write one hour under the one minute.

No, I'm keeping it all minutes and then I'm keeping it all into seconds.

So one minute there are 60 seconds, in 60 minutes there are 60 times 60, basically, which is equal to 3,600 seconds in one hour.

So in one hour there are 3,600 seconds.

What did you guess? Were you close enough? Okay, you could have estimated it by saying you know that in 60 seconds, there is one minute.

So yeah, it would be between 3,000 and 4,000.

Okay, so there are 3,600 seconds in one hour.

Now, if we wanted to do a bit of converting now, in one hour there are 60 minutes.

In 52 hours, how many minutes are there? What would you do to work it out? Well done if you said 52 multiplied by 60, which is equal to 3,120 minutes.

So in one hour there are 60 minutes.

In 52 hours, can you see 60 minutes and 52 hours, they're diagonally opposite.

If they're diagonally opposite, we're going to multiply them, okay? So in one hour there are 60 minutes, but instead of one hour we want the 52 hours.

So you would multiply 52 by 60.

So in 52 hours, how many minutes are there? 3,120 minutes.

Okay, next question.

Again, have a go.

How many minutes are there in 12 hours? How many minutes are there in 12 hours? Okay, shall we have a look together? So what would the calculation be? 12 hours times 60 minutes, well done.

Which is equal to 720 minutes.

So I like to do 12 times 6 first of all, and because I know my 12 and my six times tables, I know that's equal to 72, but it's not six, it's 60.

It's 10 times bigger.

So I'm going to multiply 72 by 10, which is 720.

So 12 times 60 is equal to 720.

In 12 hours there are 720 minutes.

Say it again with me.

In 12 hours there are 720 minutes.

Okay, well done.

Right, this time we're doing something a bit different.

I haven't told you how many hours, instead I've given you 7,200 minutes.

I want to know what is the equivalent number of hours.

7,200 minutes is the same as saying how many hours? I'll give you some thinking time first of all.

Okay, this time we're going to be doing 7,200 minutes and we're going to be dividing by 60, okay? So 7,200 minutes, this time we're going to be dividing by 60 because we want to know the number of hours.

Again, 7,200 times 1 divided by 60.

7,200 divided by 60 is 120 hours.

So 120 hours is the same as how many minutes? 7,200 minutes.

Again, if you're not sure about how to divide, you could just take the 72 divided by 60, 72 divided by 6, sorry, you know that 6 times 12 is equal to 72.

Except you need to then make it 10 times bigger, multiply it by 10, 120.

Okay, let's have a look at another one.

In one minute there are 60 seconds.

And in 1,200 minutes there are.

What mistake has been done here? What mistake has been made in the layout? Can you see a mistake? The number of 1,200 minutes, is that under the seconds or should it be under the minutes? It should be under the minutes.

So I'm going to go back and show you how I've always liked to lay out.

So you've got the hours and then the minutes under each other.

And over here, got the minutes under each other.

And then the hour over here, minutes under each other.

And then over here, what mistake has been made? 1,200 minutes.

Do I lay it under the 60 seconds? No, I should be under the one minute.

Okay, now could you please pause the video and have a go at the independent tasks that I have left for you to do.

Once you have done that, then come back and we can check and mark the answers together, good luck.

Okay, welcome back.

How did you find that? Was that okay? Right, let's go through the answers together now.

So, I left you with this table to complete and we've got our seconds, we've got our minutes, and we've got our hours, and we're trying to convert between seconds and minutes and hours.

So, the first one says 24 hours.

How many minutes in 24 hours? So that's a day.

How many minutes are there in one day? We know, what do we know? In one hour there are 60 minutes.

So in 24 hours there are 1,440 minutes.

So one hour is equivalent to 60 minutes, 24 hours would then be 24 times 60, which is equal to 1,440.

So give that a tick if you put that.

Okay, so then how many seconds are there in one day? So it's easy to work through from hours to minutes and seconds, rather than skipping from seconds to hours or from hours to seconds.

That's my preference anyway.

So we know how many minutes there are in one day, so now what's that the equivalent to? What's that the same as saying how many seconds? So in one minute there are 60 seconds.

So in 1,440 minutes there are.

We multiply it by 60 and we get 86,400 seconds in one day.

So lot of seconds.

So well done if you got that right, give it a tick.

Okay, let's look at the next one.

This time we don't have the number of hours, but what do we have? We have got the number of minutes, 2,880 minutes.

We want to know what's that the same as in hours? So in one hour there are 60 minutes, so how many hours is the same as 2,880 minutes? Again, my minutes, I've checked.

I want you to do the same if you've laid it out are under each other.

And then I'll put a question mark, because we don't quite know how many hours are in 2,880 minutes.

And this time we are dividing.

So 2,880 divided by 60 is equal to 48.

So that's the same as 48 hours.

How many days is 48 hours? Two days.

Okay, well done.

And now, so we know two days, 2,880 minutes, how many seconds in two days? Now, I could work this in one of two ways, okay? First of all, I could convert it as we have been doing.

Or if I know there are 86,400 seconds in one day, how can I find the amount of seconds in two days? I would just double my answer from before, wouldn't I? So 86,400 times 2 or double it and that should give me.

But if I wanted to convert it, I would also write it and lay it out as we have been doing.

In one minute there are 60 seconds.

So in 2,880 minutes there are.

We multiply it by 60 and that gives me 172,800.

So, well done if you said that, give that tick.

And then last one, this time we've got 36 hours.

How many days are in 36 hours? So we know that one day is 24 hours, two days is 48 hours, and 36 lies between one day and two days, so 36 hours in one day and a half, a day and a half.

So in half a day there are 12 hours, add 24 hours gives us 36.

So now what we need to do is we need to convert.

So now we've got 36 hours in a day and a half would give us 2,160 minutes and 129,600 seconds.

And also, what you could do is check that your 36 hours, your 2,160 minutes, and your 129,600 seconds lies between the 24 hours and the 48 hours.