Transcript Map Skills

Map Skills
Chapter 4 – Grid
References
Grid Squares
• If you look at a map you will notice that it is
covered in squares.
• These squares make up a grid that covers
the whole area of the map. The lines are
grid lines and allow you accurately to locate
points on the map.
• This system also allows you to route plan
using grid references (GR). For ease, the
numbers are printed around the grid and
inside at every 10th grid line in both
directions across the map.
• These grid lines belong to a much bigger
system that covers the UK and is known as
the National Grid (no connection with the
electricity supply!).
The Grid System
• Every grid system must have a starting
point so that the grid can be built up from
it.
• To cover the UK there is a need for seven
100 kilometre lines of easting’s (vertical
lines) and thirteen 100 kilometre lines of
northing’s (horizontal lines) from the
starting point.
Navigating from Grid Squares
• It is fairly easy to locate an object within a
1km square as long as you know what
square it is in.
• This can be done using Easting and
Northing to indicate the south west (SW)
corner of the square you wish to identify.
• By using the SW corner of the square, the
grid reference is standardised so everyone
knows what it means.
6-figure grid references
• To give a 6-figure reference you mentally divide
the grid into ten parts and estimate how far into
the square the object is (say 4).
• Once this is done add the figure to the first
(giving 334)- now you have your easting. Repeat
the process for the northing (eg. 255) and you
will end up with a 6-figure reference number
(334255).
• Judging tenths across the square (both up and
down) may be difficult to begin with but with
practice it soon becomes an easy system to use
Test (woopdeedoo)
Answers!!!!!!!!