GRID REFERENCES MADE EASY

GRID REFERENCESMADE EASY Produced by David Morris

A GRID REFERENCE is a number which gives a location on a map They are very useful in Scouts when we’re out hiking We can use them to find out where we’re supposed to be… ...or if we get lost we can tell someone where we are

The grid references we usually use are SIX FIGURE references They will look something like this: 216409 A bit like a phone number

These numbers refer to the GRID which covers all maps Here they’re marked in PINK so you can see them, but they’re usually BLUE

42 41 40 20 23 21 22 The grid is labelled with GRID NUMBERS at the bottom and left sides of the map

The numbers at the bottom are called EASTING because they show how far East you are. They label these lines… 20 23 21 22

42 The numbers at the side are called NORTHINGS because they show how far North you are . They label these lines… 41 40

Each Easting refers to the column to the right of it’s grid line 21

Each Northing refers to the row above it’s grid line 40

NORTHING EASTING Where are these EASTINGS and NORTHINGS in the Grid Reference? 216409 40 21

Both numbers combined give a square on the map... The grid reference of this square is 21 40 40 21

How do you remember WHICH COMES FIRST though? EASTINGS FIRST One way of remembering is to read the numbers ALONG the bottom (EASTINGS) and then those UP the side (NORTHINGS) because you go ALONG the hallway in a house before going UP the stairs

EXERCISE ONE FIND THE SQUARE You’ll have a map between two, and a list of 6 figure grid references - just find the big square for each one

6 9 OK so we now know how to find the square from these numbers: 216409 40 21 But what about these ones? What are they for?

1km Well the 40 and 21 only give you a big square one kilometre wide! Not much use if you need to know where to go exactly! 40 21

So we split each square into 100 smaller squares...

9 8 7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8 9 Each square is labelled like the grid before, but with just one number from 0 to 9

So, same as before, a square is identified by an EASTING and a NORTHING Remember, EASTINGfirst 9 8 7 6 5 4 3 2 1 0 So what’s the two numbers which identify this square? 0 1 2 3 4 5 6 7 8 9

That’s right: 4 and then 7 4 first as it’s the EASTING 9 8 7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8 9

Then 7 as it’s the NORTHING 9 8 7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8 9

42 41 40 20 23 21 22 OK, let’s put it all together… See the spot height marked 375 in the square below?

42 41 40 20 23 21 22 Let’s find out it’s full 6 figure reference _ _ _ _ _ _ First, what square is it in?

42 41 40 20 23 21 22 Yes, 21 - 40 But where does this fit into the 6 figure reference?

42 41 40 20 23 21 22 2 1 _ _ _ _ 21 first

42 41 40 20 23 21 22 2 1 _ 4 0 _ Then 40

42 41 40 20 23 21 22 Both together... 2 1 _ 4 0 _

42 41 40 20 23 21 22 Now we need to look at the missing two figures: 2 1 _ 4 0 _

42 41 40 20 23 21 22 2 1 _ 4 0 _ So we add the grid - usually you do this in your mind

42 41 40 20 23 21 22 2 1 _ 4 0 _ The spot height is in this square

9 8 7 6 5 4 3 2 1 0 2 2 0 1 2 3 4 5 6 7 8 9 Zooming in... 2 1 _ 4 0 _ 2 2

42 41 40 20 23 21 22 So now we have the full grid reference: 2 1 2 4 0 2

42 41 40 20 23 21 22 OK, what about the station in Llangollen? _ _ _ _ _ _

42 41 40 20 23 21 22 Answer: 214422

42 41 40 20 23 21 22 OK, where’s this one... 204408

42 41 40 20 23 21 22 204408 Answer: Bank Fm

EXERCISE TWO PRACTISE MAKES PERFECT You’ll have a map between two, challenge each other to give the grid ref for a place, and the places for given refs

GRID REFERENCES MADE EASY