Lesson video

Hello, my name is Miss Gilyeat and I'm your geography teacher for today.

In today's lesson, we are going to be learning about how we can use four and six-figure grid references to find places on Ordnance Survey maps.

Let's get going.

Our lesson outcome for today is that you can use four and six-figure grid references to locate features on an OS or Ordnance Survey map accurately.

We have three keywords for today's lesson.

The first keyword is northings, which are numbered horizontal grid lines found on maps.

Eastings are numbered vertical grid lines found on maps and a grid reference is a number which combines northings and eastings to help you locate a feature on an Ordnance Survey map.

These three keywords will be highlighted in bold throughout the lesson, so you can always refer back to them if you need to.

We have got two learning cycles for today's lesson.

Our first learning cycle is we're going to learn how we can give a four-figure grid reference on an Ordnance Survey map.

We are then going to learn how to do a six-figure grid reference on an Ordnance Survey map.

So let's get going with the first learning cycle on four-figure grid references.

Now, Ordnance Survey maps have faint blue lines over the top of them.

These are called grid lines.

We can use them to help locate places on a map.

So if we have a look at my screen here, we have got a snapshot of an Ordnance Survey map of Whitley Bay.

So if we look at that carefully, you can see those faint blue lines.

So we've got two purple arrows there showing them where they've located.

And you'll notice that over these lines at the bottom and on the right hand side of the map there are numbers which are also in a faint blue colour.

Okay, so we're going to learn how we can use these lines and the numbers to come up with a grid reference.

Okay, so the lines which are running vertically across the map are called eastings, okay? And these have got numbers at the bottom, as you can see here.

So the lowest number here is 32 going up to 40 or nearly 41.

You can see it on the map.

Now the numbers increase as you move further east.

The lines which are running horizontally across the map are known as northings, okay? And these lines run from left to right and you can see here that there are numbers going up on the side from 70 to 76.

As you move further north, the number increases in value.

Now together, these eastings and northings create a grid and therefore a grid reference, which helps us point or pinpoint specific locations within a map.

Let's check our understanding.

So true or false? Northings are vertical lines on an Ordnance Survey map.

That is false.

Can you tell me why? Northings are horizontal lines on an Ordnance Survey map while eastings are the vertical lines.

To find the number of the grid square, we look at the bottom left corner of where the square is that we want to locate, okay? So for example, if I want to find out what the grid reference for that square is there.

So just north of Whitley Bay, you might be able to tell that there is a church in there.

There is an A road and some housing.

Okay? So there's the grid square we want to locate.

Now the point that we are looking for is the bottom left hand corner of the grid square, and where those lines meet are the numbers that we are going to read off, okay? So to find a grid reference of that square, we first go along the corridor and we go east, okay? And that brings us to number 34.

Now we can see there that I've highlighted 34 and written it again black at the bottom to make it a little bit more obvious.

But sometimes it is a bit tricky to read the numbers because often they are in faint blue and they're on top of the lines.

So you have to be really careful there to read the right number, okay? So that takes us to number 34.

We then go up the stairs as we like to say in geography.

So we're going further north, okay, to find the line, the horizontal line at the bottom of the grid square.

So we can see there, that's taken us to 74.

Okay? Now that gives us a four-figure grid reference of 3474.

You'll notice there that we don't use commas, we just write the numbers as they are.

So 3474 is our four-figure grid reference for that square.

Okay, let's check your understanding.

What is the four-figure grid reference for St.

Mary's Island? Now to help you out, I've circled where the island is located, okay? So is it A: 3872, B: 3275, or C: 3575? Have a go.

The answer is, of course, 3575.

So I went along the corridor, that brought me to 35, up the stairs to 75.

And remember, you are always looking for the bottom left hand corner of where the grid square meets.

Okay.

What I would like you to do is, first of all, have a go at Task A1, which is to give the four-figure grid reference for the different coloured circles, okay? Pause the video and have a go at this first task.

Your second task for Task A is I'd like you to use the map and the key to find the four-figure grid reference for Flamborough Head, the train station at Filey and the information centre in Bridlington.

So you'll have to use the key of the Ordnance Survey map to know what some of these look like on maps as well.

You might know already, but if you don't, they will be on the Ordnance Survey map key, okay? So pause the video and have a go at the questions.

Okay, let's go through our answers for this.

So for task one, the pink circle, the grid reference is 3275.

The red circle is 3373.

The yellow circle is 3671, and the green coloured circle is 3271.

How did you do? Okay, so now we have got the four-figure grid reference for these places.

So A: Flamborough Head was 3365, the train station in Filey, so that's a little pink dot on a black line, is 3266.

And finally the information centre, which is an "I" in a little blue box, in Bridlington, it was 3264.

So well done if you've got all of those right.

Okay, so we are now moving on to our second learning cycle, which is about how we can give six-figure grid references on a map.

Now this is a tricky skill, so we're gonna have to concentrate really hard.

Now, what a six-figure grid reference does is help us find an exact point within a grid square, okay? Which gives us a more precise location up to about 100 metres.

Now it's called a six-figure grid reference because they consist of six numbers.

So if we have a look at the example below, we've got one, 274 652.

Again, you will notice that there is no commas within the grid reference.

Now, the first three numbers are eastings, okay? And the last three are northings.

So we're gonna learn now of how we can give, or find a six-figure grid reference.

Now let's check our understanding first of all.

So, true or false? Six-figure grid references give more precise locations than a four-figure grid reference.

That is, of course, true.

Can you tell me why? So six-figure grid references find the exact point within a grid square, whereas a four-figure grid reference just gives you the grid square.

Okay.

So, to find a six-figure grid reference, we divide a whole grid square into 100 smaller squares.

Okay? Now, I've got an image of what this would look like on the slide here.

So on the right, you have got a total grid square.

Now for a six-figure grid reference, you've got to imagine there are 10 extra miniature lines going across that way and 10 going vertically as well, okay? Now these lines will then be numbered from 0 to 9, horizontally and vertically.

Now in real life, these lines will not be shown on a map.

So you have to estimate, which is why finding six-figure grid references can be quite tricky.

Okay, so I'm gonna show you how you would work one out.

Now on the slide here, we have got one grid square, okay? Now you'll see in my grid square that we've got the sea and there is a little lighthouse, okay? On the end of the the peninsula, okay? Now the four-figure grid reference for this square is 25 84.

So you can see the numbers in black at the bottom.

But what we want to do is find out exactly where in that square the lighthouse is.

So it's the third and the sixth-figure which tells us that.

Now I've put on the slide here, 25 84, and I've left a space after the 25 and I've left another space after the 84.

So what we do is, again, we imagine that there are 10 lines or nine lines, actually, nine lines going across the grid square and either direction, okay? So 100 little squares.

So there's the lighthouse, okay? Now, if we were to go along, okay? We would like go along the corridor, like we would with a four-figure.

That brings us to 25 6, okay? And 84 7.

That is the exact point within the grid square.

256 847.

And that is your six-figure grid reference.

Okay.

Here I have given the four-figure grid reference for the lighthouse in Godrevy Island, okay? So it's 5743.

The six-figure grid reference is 576, because it's roughly six along in the grid square and 435, 'cause it's roughly halfway up the grid square.

Okay, let's check our understanding.

What I'd like you to do is write down the third and sixth-figure for these grid references of the different coloured circles.

And in doing this, you are giving a six-figure grid reference, okay? So pause the video and have a go at finding the third and the sixth-figure for the different coloured circles So how far along and how far up each grid square it is.

Okay, let's go through our answers for this slide.

Okay, so the pink circle, the six-figure grid reference was 325 755.

That's because that pink circle is bang on in the middle of that grid square.

For the red circle, the six-figure grid reference was 332 736, 'cause it was just a little bit within the grid square and then it was quite far up it.

For the yellow circle, the answer is 362 718.

And the green circle, the answer was 324 711.

If you were just one out with that third and that sixth-figure, I wouldn't worry too much because as we said earlier, we do have to estimate, okay? So it is quite hard sometimes to get the exact location.

Okay, so we're onto Task B now.

What I would like you to do is find the six-figure grid reference for the Lighthouse Tynemouth School, the Oceanarium and King Edward's Bay Beach.

Now be careful of question four, I'm asking for where the beach is, not the bay.

Okay? Pause the video and good luck.

Let's go through the answers for these questions.

So, for question one, the answer for the lighthouse, which I've circled there, was 382 690.

And as you'll notice, it's fine to put a zero for those questions.

If something is actually on the line, absolutely fine to put a zero.

For the school, okay, the answer was 366 694.

For the oceanarium, the answer was 364 705.

And for King Edward's Bay Beach, so I was looking for the beach here.

The answer was 372 695.

Well done if you got all of those correct or just one or two wrong, 'cause they were quite tricky questions.

Here we have a summary for today's lesson.

So maps have grid lines called eastings and northings, which help us locate places on a map.

Each grid square has two sets of numbers, giving a four-figure grid reference.

And six-figure grid references give us an exact location within a grid square and are more accurate.

Okay, that's it for four and six-figure grid references.

Now well done because there's some really quite tricky map skills working there.

So you've done a fantastic job.

I've really enjoyed teaching you today, and I'll see you next time.

Bye.