# Lesson video

In progress...

Hi, everybody, I hope you're all well.

Today we are going to be comparing time graphs.

So what you need to do is to put on your hats, choo, tighten your ties, ch, ch, ch, choo, and tell the computer, "Now I'm a mathematician." Great, let's get started.

For this lesson, the following resources that you need are a pencil, a piece of paper and a ruler.

If you need any of those things, please pause the video now and go collect them.

Great, let's get started.

So here is our lesson agenda.

First off, we're going to be looking at our Star Words.

If we're looking at two graphs, what's the same and what's different? We're then going to be asking questions, and then it will be your End of Lesson task.

So here are our star words.

So today we're going to be looking at time graphs.

We're going to be comparing, looking at scales, reading data.

We have our axis, which is the vertical and the horizontal.

So here we have the temperature recorded in New York on a Sunday.

You can see the times along the top and the temperatures along the bottom in degrees Celsius.

And here we have an empty bar chart.

How should the axes be labelled? What should go along this horizontal? Well, the horizontal we can see are the times, so we could call it times that the temperature recorded or times during the day.

And then along the vertical, we have the temperatures.

So we could just call it Temperatures.

How should each piece of data be plotted? Now we know that when we plot on time graphs, we do a little cross at each point.

So here we could see that we've plotted our data on to our bar, I'm sorry, on to our time graph.

Now, what statement could describe an aspect of the time graph? Now I'm going to have a look at 6:00 a.

m.

And at 6:00 a.

m.

, the temperature was 8 degrees Celsius.

And I can see this because if I go to 6:00 a.

m.

and go up and then across, the temperature reading was 8 degrees Celsius.

And that's the same for at midnight.

At midnight, it was also 8 degrees Celsius.

And here we have our curve.

I've drawn in our curve to help us read our graph.

And we can see, there is an upwards trend before midday, and then it's starting to get colder.

So we can also say, generally in New York, on this particular Saturday, it was cold to begin with, it got warmer, and then it got colder towards the end of the day.

Here we have the temperature recorded on Saturday and Sunday.

What could we say between these two graphs? Well, let's have a look at the temperature at 6:00 in the morning on both days.

On Saturday, the temperature was 8 degrees Celsius, and on Sunday, the temperature was also 8 degrees Celsius.

Let's have a look at another time.

How about 6:00 in the evening? On Saturday, it was around 9 degrees Celsius.

And on Sunday, it was 10 degrees Celsius.

So it's 1 degree warmer on Sunday than it was on Saturday.

How about midnight? Now I can see midnight on Saturday was 8 degrees Celsius, and midnight on Sunday was also 8 degrees Celsius.

And then we always draw in the curvature of the lines as well.

So really important when we are drawing and constructing our time graphs, we need to make sure we draw that curvature of the line to help us and anyone reading our time graphs to be able to read it and interpret it clearly.

So here we have two constructed time graphs, and your task today is going to be using those time graphs that we looked at together and answering these questions and then comparing the two.

So we have eight questions here.

Let's go through them together.

Question one.

On which day was it warmer at midday? Question two.

What was the difference between the highest and lowest temperature on Saturday? Question three.

What was the difference between the highest and lowest temperature on Sunday? Question four.

At what time was it the team temperature on both days? Question five.

What was the lowest recorded temperature over two days? Question six.

What was the difference between the temperature at 3:00 on Saturday and Sunday? Question seven.

Was there a bigger change in temperature between 12:00 and 9:00 on Saturday or Sunday? Explain.

And question 8, at every recorded time, it was always either the same temperature or warmer at the same time on Saturday as it was on Sunday.

So pause the video and use the two time graphs to help you.

Welcome back, everyone.

My name is Miss Jones, and I'm going to be taking you through today's answers.

If you've got one, grab a different colour pen or pencil, ready to do some ticking and some fixing.

Okay, number one.

Which day was it warmer at midday? It was Sunday.

What was the difference between the highest and the lowest temperature on Saturday? That was 6 degrees.

Number three.

What was the difference between the highest and lowest temperature on Sunday? That was also 6 degrees.

Number four.

At what time was it when it was the same temperature on both days? Oh, there were two of these, so hopefully you spotted both of them.

Have a look at the graph if you didn't.

It was 6:00 in the morning, 6:00 a.

m.

, and midnight, 00:00.

What was the lowest recorded temperature over the two days? It was 6 degrees.

What was the difference between the temperature at 3:00 or 15:00 hours on Saturday and Sunday? That was 2 degrees.

Was there a bigger change in the temperature between 12 and 9:00 on Saturday or Sunday? Explain your choice.

So the temperature change was actually the same.

I've put here, on Sunday it dropped 4 degrees, and I've put then the details, 13 down to 9 degrees, and on Saturday it also dropped 4 degrees from 12 degrees to 8 degrees.

And finally, number eight.

At every recorded time, it was always either the same temperature or warmer at the same time on Saturday as it was on Sunday.

Is this true or false? Can you prove your answer? It was false.

It was actually warmer on Sunday throughout a lot of the day, but you might've noticed at 9:00, it was warmer on Saturday.

Make sure you've explained your answer for that one in order to get it right.

If you haven't, perhaps you might want to add an explanation now.

Okay, well done, everybody.

If you need to pause the video and look at those again, feel free to.

I'm going to hand you back over to Miss Hill to finish the lesson.

Well done, everyone.

Give yourselves a big pat on the back.