Copies of the maps that students will color. Students will probably color more than one map during a class period. It is good to have a variety of maps for them to choose from and attempt to color. The following maps can be used, or you can make others.
Coloring materials. Crayons are usually better than markers because they don't run out when coloring large areas.
Colored marking pieces, such as poker chips or unifix cubes. They are useful for planning how to color a map without actually marking the paper, so it is easy to make changes.
Overhead transparencies of maps that students will color are useful for demonstration purposes.
Invite the children to work singly or in groups (whichever they
prefer)
to try to discover the smallest number of colors needed to color the map.
After some problem-solving, have the students discuss (and perhaps
write about) their results, their strategies and reasoning and the
observations that they made about the problem.
Replay with more complex maps. In
order to have a variety of maps to work with, you can draw
additional ones that will be appropriate for your students.
Show children that they can draw their own maps to share with one
another and try to color them.
Show students how they can experiment with various colorings
without using up so many maps, or having to take the time to color
them by marking regions with unifix cubes or other colored marking
pieces instead of coloring them in.
Read or tell A Television Story . What does
the problem in this story have in common with the map coloring problem?
Talk about the maps that you colored. How many colors did you
use to color each of them?
How did you go about coloring the maps? On the chalkboard, write down descriptions
of the strategies that the students used. It might be useful to give
the strategies names.
Are there certain strategies that worked better for one map than
they did for another?
Is there any strategy that works for all maps?
Are there good strategies for determining if a particular
number of colors is enough?
Can you look at a map and tell for certain how many colors it
will need?
Can you find a map which you are sure will require 3 colors, or 4
colors to color properly?
Show students some maps and have them guess how many colors
they think it will take. What do you pay attention to when you are
making such a guess?
What other maps did you make that were interesting to try and
color? What made them interesting? Were they easy or hard to do?
