Coordinate system for grade 7 students

1. Locating Places
How do you find a city or other location on a world map or globe?
It might be easy to find Dallas, Texas, but what if you were asked to find
San Miguel, Argentina? Where would you begin to look?

2. Where Do We Look?
Searching for places on a world map or a globe can be time
consuming and frustrating. Sometimes you don’t know
where to begin looking!
You can find a place more quickly if you know its address.
• You can find your seat in the football stadium if you know
you are sitting in Section 107, Row M, Seat 9.
• Friends can find your house if they know you live at 4120
Viola Drive.

3. Where on Earth?
All places on Earth have a specific address. This address
makes it easy to find a place.
Places on Earth do not have addresses like Row M, Seat 9
or 4120 Viola Drive.
The addresses of places on the Earth are given in latitude
and longitude.

4. To help us locate places on the earth’s surface, we use a coordinate
system. This coordinate system is like placing a giant grid over the
earth. This grid has lines extending from east to west called lines of
latitude and lines extending from north to south called lines of
longitude.
The coordinates of a location are like an address for that place. If you
know the coordinates (like 34° South Latitude and 58° West
Longitude), you can easily find any place on the earth’s surface.

5. About Latitude
Lines of latitude extend east and west across the Earth. These lines are
imaginary. We cannot actually see a latitude line on the Earth. Latitude is
measured both north and south from the Equator and is measured in
degrees (°).
The Equator is
at 0° latitude. It is
neither north nor
south. It is at the
center between
north and south.
The South Pole
is located at 90° S.L
40° N.L. is the 40° line of
latitude north of the
Equator.
40° S.L. is the 40° line of
latitude south of the
Equator.
The North Pole is
located at 90° N.L

6. Degrees of Latitude
Lines of latitude
are numbered
from 0° at the
Equator to 90°
N.L. at the North
Pole. Lines of latitude
are numbered
from 0° at the
Equator to 90°
S.L. at the South
Pole.
]
[
90
80
70
60
50
40
20
30
10
90
80
70
60
50
40
20
10
30
N
S

7. The equator (0° latitude) splits the Earth into two hemispheres -
the Northern Hemisphere and the Southern Hemisphere.
N
EQUATOR
S
Places located north of the Equator have a North Latitude (N.L.) address.
Places located south of the Equator have a South Latitude (S.L.) address.
Northern Hemisphere
Southern Hemisphere

8. Longitude
Lines of longitude extend north and south. Like lines of latitude, these lines
are imaginary. We cannot actually see a longitude line on the earth. Longitude
is measured in degrees (°) from the Prime Meridian. Lines of longitude are
evenly spaced at the Equator, but meet at the poles.
Lines of longitude begin at the
Prime Meridian. The Prime
Meridian is located at 0°. It is
neither east nor west. It is
between east and west.
60° E.L. is the 60°
line of longitude
east of the Prime
Meridian.
60° W.L. is the 60°
line of longitude
west of the
Prime Meridian.
W E

9. East
Longitude
West
Longitude
Prime Meridian
N
W E
S
180°
North Pole
Lines of longitude are numbered east from the Prime Meridian to the 180°
line and west from the Prime Meridian to the 180° line.
Longitude

10. Western Hemisphere Eastern Hemisphere
Prime Meridian
The Prime Meridian (0° longitude) and the 180° line split the earth into two
hemispheres - the Western Hemisphere and the Eastern Hemisphere.
Places located east of the Prime Meridian have an east longitude (E.L.) address.
Places located west of the Prime Meridian have a west longitude (W.L.) address.

11. When geographers use the term “absolute location” they are
referring to the global address of a place.
Absolute location is the location of a place on the earth’s surface stated in
terms of latitude and longitude.
To find the absolute location of a place on the earth’s surface:
• First, look if it is in the Northern Hemisphere or the Southern
Hemisphere.
• Then, look if it is in the Western Hemisphere or the Eastern
Hemisphere.
• Finally, find its exact location using lines of latitude and longitude.

12. N
W E
S
For example:
Mexico is in the Northern Hemisphere because it is north of the Equator.
Mexico is in the Western Hemisphere because it is west of the Prime
Meridian. Point to the country of Mexico. (25° N.L., 110° W.L.)

13. Look for the circle around Mexico. Were you correct?
Mexico’s global address is about 25° North Latitude and 110° West Longitude.
So the absolute location for Mexico is 25° North Latitude and 110° West Longitude.
N
W E
S

14. Checking Up
1. The Equator is the imaginary line that separates
a. the Eastern Hemisphere from the Western Hemisphere.
b. the Northern Hemisphere from the Southern Hemisphere.
2. A location that has a global address of 35° N.L. and
110° E.L. is located in the
a. Southern and Western Hemispheres
b. Southern and Eastern Hemispheres
c. Northern and Western Hemispheres
d. Northern and Eastern Hemispheres