Title:  Maps: What Do They Really Show?*

Grade Level:  7-9

Subject and California State Standards met:  Math, Geography, History

Overview:  Students will compare the Mercator and Peters projection maps.  They will discuss the differences and use critical thinking to relate their discoveries to current social situations.

Purpose: To encourage students to develop a critical and logical outlook on knowledge in general.



  1. Several Mercator projection maps - these can often be borrowed from other classrooms.
  2. A Peters projection map large enough to display on the blackboard or wall.
  3. A World Atlas
  4. Website of interest www.rethinkingschools.org

Activities and Procedures:  

  1. Opening questions:  What are maps?  Is it possible to accurately represent a sphere on paper?  Do all maps of the Earth represent it in the same manner?  
  2. Possible answers - A world map is a flat representation of a spherical object - the Earth.  Unfortunately all world maps are misleading because it is impossible to accurately represent a sphere using a 2-d projection.
  3. Show the class a Mercator projection map.  Most students in the class will have seen this map before.  Give them some background information on the map.  The Mercator projection was developed in Germany in 1569 during the European Expansion.  Colonial maps needed to be accurate to navigate by in order not to repeat the Columbus disaster.  See Notes on Mercator and Peters projection maps for more details.
  4. Give each group of three- four students a Mercator projection world map.  Tell them that Mexico is 761,602 sq. miles.  Provide each group with the Land Area Measurement and Comparison handout which asks them to use Mexico as the unit of measure to estimate the areas of land of other places such as Alaska.  Students may attempt to complete this in many ways.  Some may trace Mexico and see how may times it fits in other countries.  Others may use rulers or grids to estimate how many square centimeters are in Mexico and compare that to other countries.  Some may trace Mexico then rearrange the shape to make it more rectangular.  If you are using this as a math class you can use centimeter grids and focus on areas, ratios, and fractions.
  5. Once a group finishes have them look up the actual areas of each country and write it on a poster or the blackboard.  For teachers without access to a world altlas see the information page.  Groups can present different methods used for calculating their values.
  6. Lead a discussion of the discrepancies.  Why are our estimates so far away from the given values?  Why does Alaska look so much bigger than Mexico?  How do Greenland and Africa compare visually, number wise?  
  7. Post the Peters projection map in comparison.  What is different?  Give a brief background on when the Peters projection was created and with what purpose.  Compare and contrast with the Mercator's  projection map. See Notes on Mercator and Peters projection maps.  There is a useful statement Ward Kaiser wrote when describing the Peters projection, “Peters is ...clearly focused on justice for all peoples, recognizing the values and contributions that all nations and all cultures can bring to the emerging world civilization.”

 Have students respond in writing to three of the following questions.

  1. Student could share their answers in small groups or with the class as a whole.  This discussion may go in many directions.  Some students may feel cheated or skeptical, others may rationalize the differences.  Some may claim the map is biased against the Southern Hemisphere or racist.  Some students may begin to question other information they are being taught, and begin to look for alternative sources of information.  You know your students best and can help direct the conversation appropriately.

Tying It Together:  How does this apply to your life?  How can students verify questionable information?  What other sources of information are there?  Take action to bring more Peters projection maps into the classrooms.

*Adapted from Rethinking our Classrooms Vol. 2, Math, Maps, and Misrepresentation by Eric Gustein.

Kaiser, W.L. A New View of the World:  W Handbook to the World Map: Perters Projection, Amherst MA: Friendship Press, 1987