As you've just seen, it can be difficult to find geographic relationships among data presented in a table. Plotting that data onto a map can make it easier to identify any relationships that may exist.
Maps help us to precisely locate places on Earth. Imaginary
lines running north-south and east-west form a grid
that can be used to describe any location on the globe.
Using the grid is very similar to the x-y plotting you
use in mathematics classes. The x-axis on Earth is the
equator and the y-axis is the prime meridian. The position
of any point on Earth is reported with reference to
these two special lines.
the buttons to turn the latitude and longitude lines
and grid on and off. Read the caption under the graphic
for each type of line. With a partner, discuss any methods
you know of that can help you remember the differences.