Lesson video

Hello, my name is Miss Giliet and I'm going to be your geography teacher for today.

In today's lesson, we are going to be learning about scale and distance on maps and this is part of the what makes a geography topic.

We've got loads of geography skills to learn about, so let's get going.

Our lesson outcome for today is that we can use maps at different scales to investigate an area and measure distances.

We have got three key words for today's lesson.

We'll be using these throughout the lesson and they'll be highlighted in bold to make sure that you know what they are.

So the first key word is scale.

Scale shows what the size, the area that is represented on the map really is.

So what it is in real life.

A key explains what the difference symbols, marks, and colours used on the map mean.

And a symbol is a mark shape or abbreviation that represents a landmark, feature or area of a map, diagram or drawing.

There are two learning cycles for today's lesson.

The first learning cycle is we are going to learn what a scale on a map or what is a scale on a map.

And for the second learning cycle we're gonna find out how do we measure distances using scale? Let's get going with our first learning cycle, what is scale on a map? Now, the scale of a map explains how large an area shown on the map is in real life.

Now, different types of maps have different scales.

So on the slide here we can see there are two different maps.

Can you tell me what one of them is? So we have an ordinance survey or an OS map or a section of an OS map on the left, and then we've got a world map on the right which shows the oceans have been marked on there.

Do you want to have a go at naming the seven continents as well? Now, both of these maps have a scale bar which allows you to work out the distance in real life.

So we can see there's a line and then it tells you at the end of the line how far that would be in real life.

So the one on the left is from zero to 10 kilometres, and you'll notice there's a ratio there as well, which says one to 100,000.

We're going to learn what that ratio means in a minute.

And then the world map has a different scale.

So again, there's a line which shows the measurement, and if you were to measure anywhere on that map that's the same distance as that line, it would be 5,000 kilometres.

Small scale maps show a large area but have little detail.

For example, a world map.

Okay? So this is one of the biggest maps that you get, really, because it's of the whole world.

So you've got a very, very large area, but you don't put too much detail on the map.

Can you think why you don't put too much detail on? If you put too much detail on the map, you wouldn't be able to see anything because it would just be absolutely crammed full.

Okay? So that is why in general, large maps won't have as much detail of small areas.

Now, I've got a question for you.

Can you think of any other examples of small scale maps? Have a think so you could discuss with your partner or just have a think by yourself.

Izzy's got an answer for us here.

A country map is small scale.

Izzy is absolutely right.

So even though a country is obviously smaller than a world map, it's still a very, very large area.

So a country map might show the main cities in the area, it might show mountain ranges, but it's not gonna show you small things like path routes or where the schools are or where hospitals are because there'd be too many to put on one map.

Now, large scale maps show a smaller area in more detail.

For example, a town or a local area.

So on the slide on here, we have got a picture of a zoomed in ordinance survey or OS map.

Now, this map is so zoomed in that you can actually see the individual buildings on the map.

Looking at that, can you see any other things on the map that you recognise from the symbols? I can see the beach on the left, there is a train station, there is a school, there's even a caravan site.

All those little pictures, those symbols, are all represented on this large scale map.

I've got another question.

Can you think of any other examples of large scale maps? So on the slide here we've got examples of small scale and large scale ones.

So a small scale map would include a world map, a continent map, or a country map.

Large scale maps include maps of local areas or a map of a town or city.

Let's check our understanding.

Which of the following is a small scale map? A, map of a local town? B, a world map? Or C, map of a theme park? Pause the video and have a go.

The answer's B, a world map.

So a large area but in little detail.

Now, the scale on an OS map shows the relationship between the map and real world distances.

Now, as I said earlier, OS maps, you have a ratio to represent this.

So an example of a ratio might be like the one I've got on the slide here, one to 50,000.

Now, that means that if you were to measure one centimetre on the map, anywhere on the map, that would represent 50,000 centimetres in real life.

Now, different types of maps will have different scales.

So you might have one to 50,000, you might have one to 100,000, you might have one to 25,000.

It depends what you're using the map for to look at.

I've got a question.

Why do you think there are OS maps at different scales? So why do you think you have some larger scale ones? So more zoomed in or why do you think you've got some small scale ones? So having a larger area.

Have a think.

Now, you'll use different scale OS maps for different purposes.

You may use a small scale map, which remember, is a large area in little detail, to plan a road trip around the country.

Okay? A good point about having a large area is that you can see what towns and cities are close to each other.

So if I was going to plan a route up from the south coast of the UK, all the way to Northern Scotland, I might want to have a look at a map of the whole country to decide where I am going to stop off on the way.

Okay? It might not show me my individual hotels or roads or paths that I would take, but it does give me a general idea of the places that I would like to visit.

The scale on an OS map will be printed in the map's legend or key.

So if we have a look on the slide here, just under the map we can see the scale bar, which has got a bar with it to show where 10 kilometres is and also the ratio just above it.

Okay? We can see there, scale one to 100,000 with the bar.

So that distance is 10 kilometres.

So these are examples of small scale OS maps or the different ratios, one to 25,000, one to 50,000 and one to 100,000.

These types of maps are used to show large areas or regions, like when I plan a road trip, for example.

Now, if we have a look at this example of a small scale map, I want you to have a think, what symbols can you see on the map? So yeah, just having a look, if you've not got the OS map key with you, it might be worth printing one out or having a look at it to refer to them.

Sometimes you can just take a guess at what the symbols mean.

So for example, the little bluebird is a nature reserve.

Okay? So what symbols can you see on that map? So what kind of detail can you see in a small scale map? And I also want you to think, what kind of symbols do you not see on the map? So what kind of detail isn't shown on there? So you may also use a large scale OS map to plan a walk in your local area so you can see all the footpaths and tracks.

Okay? So large scale maps are more for looking in an area in a lot of detail.

These are really useful if you're planning a walk.

So if we have a look at the map or the extract from a map, we can see on the slide here, we can actually see the individual footpaths, we can see the walls, we can see that there's some rocky out crops, et cetera.

So these are useful for knowing an area in a lot of detail.

Now, these are examples of large scale map ratios that ordinance survey use.

So one to 1,250, one to 2,500 and one to 10,000.

These maps show an area in a lot of detail.

Now, if we have a look on the slide here, we can see at the scale bar at the bottom of the map has got the bar, so that distance is 500 metres and you've also got the ratio.

So we've got one to 5,000 here.

So what symbols can you see on that map and why might it be useful to use those symbols? Let's check our understanding.

Where would you find this scale ratio on an OS map? A, in the legend, B in the title, or C on the back? Pause the video and have a go.

So the answer's A, in the legend.

Okay, we're onto our first tasks of the lesson.

First task is I'd like to write a short paragraph which explains the difference between a small scale and a large scale map.

My second question is, why would you take a large scale OS map, so one to 10,000, for example, with you on a walk, why would that be useful? Pause the video and have a go at these questions.

Let's see if your answers are similar to mine.

So for question one, I have put the scale of a map shows how large an area shown on the map is in real life.

Small scale maps show a large area but have little detail.

Example, a world map and large scale maps show a smaller area but in more detail.

Example, a local area.

For question two, a large scale map is better on a walk than a small scale map because large scale maps show more detail of a small area.

You'd be able to spot the footpaths and walls which would be helpful for navigating on a walk.

Now, you didn't have to write exactly those things, but you should be along those lines somewhere.

Maybe pause the video and see if you can add anything extra to your answer.

We're now onto our second learning cycle about how do we measure distances using scale.

Proper geographical skills, these ones.

Now, we can use the scale bar to measure real life distances between places on a map.

So as I said earlier, this is what a scale bar distance looks like.

You've got a line at the bottom which gives you a length and that means if you put that length anywhere on your map, that's the distance that you have got in real life.

Okay.

So they're usually located on the legend or below the map like this one.

We can use the ratio and make a calculation here as an example.

So this is how you would use the ratio to figure it out.

Now, looking at this map here of Sutton Bridge, you've got the scale bar, but the ratio is one to 50,000.

This means that one centimetre on the map is 50,000 centimetres in real life.

Okay? Now, let's have a go at actually working a real life distance out.

So the distance from New House to Westmere House Farm is four centimetres.

So I located the two places on the map.

Okay, there they are.

I used my ruler and I measured four centimetres.

Okay.

This means it is 200,000 centimetres in real life because remember, one centimetre is 50,000 centimetres.

Okay.

Now, you have to do a little bit of maths here.

There are 100,000 centimetres in one kilometre.

Okay? So we need to figure out now what 200,000 centimetres is.

So we divide it, okay? So 200,000 centimetres divided by 100,000 centimetres equals two kilometres, and that gives us our distance.

Let's check our understanding.

How many centimetres are there in one kilometre? The answer's B, 100,000.

There's actually another way we can measure distances as well.

Now sometimes using this method is a little bit quicker than using the ratio.

Now, from previous lessons or if you've used OS map skills before, you'll know that OS maps have these faint blue lines over the top of them called grid squares.

Now, if we know what the distance of one of these grid squares is, we can quickly use them to measure distances.

So for example, one of these grid squares on this map represents one kilometre on the ground, okay? Therefore, if we want to measure distances between places, we can count the grid squares.

Now, sometimes, you know, if you're measuring a distance, it's not going to be just straight up or straight across following the lines, sometimes you'll be going at a diagonal.

That's totally fine.

You just have to kind of roughly work out how many grid squares it would be.

Okay? So if we look at this example again of New House Farm to Westmere House Farm, we can work out that it's approximately two grid squares away from each other.

Okay? So even though they're not on the lines of the grid square, you can do a rough estimate.

Now, if one grid square is one kilometre and they're two grid squares away from each other, then it's two kilometres.

That's the same answer that we worked out with the ratio.

Let's check our understanding.

Grid squares can be used to measure distances.

Is that true or false? That's true.

Why is it true? Once you know the length of a grid square, you can count them to measure approximate distances.

Okay, we're on to task B for this lesson.

So you might have to use your calculator for this and that is absolutely fine.

Using the ratio one to 25,000, what would the real life distances of these distances be on a map? And I would like you to write your answer in kilometres.

So A, two centimetres, B, five centimetres, and C, 10 centimetres.

You're then going to work out the same distances on the map, but with a different ratio.

So using the ratio, one to 100,000, what would the real life distances of these on a map be? And again, I'd like you to write your answers in kilometre.

Okay? Good luck, have a go.

We're now going to use an actual part of an OS map to work out the distances between places.

So for this question, your scale is one to 50,000.

Okay? So these are the distances you need to work out.

From Westmere House Farm to Bridge Farm, the beaches to Clark's Farm, the phone box in Little Sutton to the parking in Sutton Bridge, and Nene Lodge Farm to Clark's farm.

Okay? So for this, you're going to have to locate the places on the OS map and you can either use the key, use the ratio, or you can use the scale bar.

It is up to you.

Good luck.

Let's go for our answers.

So for question one A, the answer was not 0.

5 kilometres, B, 1.

25 kilometres, and C, 2.

5 kilometres.

For question two, 2A was two kilometres, 2B is five kilometres and 2C is 10 kilometres.

Now, for the answers here, I've worked out what the distances would be in centimetres as well.

So if your answer is slightly wrong, it might be worth checking that if you got the first part of the question right, okay, or the first part of your working out right, did you work out how many centimetres it was? And from that you might be able to figure out where you've gone wrong, if you have got any wrong.

Okay.

And these were the distances using the map.

So Westmere House Farm to Bridge Farm was a kilometre, the beaches to Clark's Farm was 3.

5 kilometres, the phone box in Little Sutton to the parking was four kilometres, and Nene Lodge Farm to Clark's Farm was 0.

8 kilometres.

Now, well done if you've got those right, because those were quite tricky questions.

If you were potentially just slightly out, I wouldn't worry too much.

It means that you've just measured it slightly wrong, okay? Here's a summary for today's lesson.

The scale of a map explains how large an area shown on the map is in real life.

Small scale maps show a large area, but to have little detail, for example, a world map.

Large scale maps show a smaller area in more detail.

For example, a town or a local area.

A scale bar shows how distances between areas in real life compare with the distances shown on a map.

Now, that's it for today's lesson.

Well done because those were quite tricky geographical skills that you've had to use there.

So if you have found them hard, then I wouldn't worry about it because they are quite hard, but it might be useful to have a go at a few more practise questions to make sure that you can do scale well going into the future.

Right, I've had a pleasure teaching you.

See you later.

Bye.