How Do Cartographers Find Points on a Map?

Mauricio Gonzalez

Frederick Douglass Academy, Manhattan

Summer Research Program for Science Teachers

August 2009



Subject:  Earth Science

Grade Level: 9th

Duration:  40 Minutes

Do Now: Describe 3 different ways you would use to find any place on a map.

                 Describe what Latitude and Longitude are and how they may be used to help find a locality


     Use abstract thought and group work to create a coordinate system

  • Follow instructions given for locating a point on a map


    Vocabulary:  Coordinate system, Mercator, Latitude, Longitude



    In this activity, groups are challenged to devise a coordinate system which can be used to communicate the position of a point.


    1.    Give each group a practice paper with a black dot marked on it. Explain that their challenge is to devise a system of communicating the position of a dot such as this to someone who cannot see the paper. 

    2.    Give groups 10-15 minutes to devise their system.  Their only materials are the paper and a pencil.

    3.    Divide each group into two teams and separate the teams on opposite sides of the room.

    4.    Give one team a test sheet with a black dot marked on it.  Give the other team a blank sheet of paper.  The task is for the first team to communicate the position of the black dot to the second team so that they can reproduce it on their blank page.

    5.  Scoring will be done by putting a transparency over the test sheet, marking the position of the dot and then positioning the transparency over the second page to see how closely the position of the dot matches.  The distance between reproduced and original dots will be measured in millimeters. 


    Practice/Share or Log Entry:

    1.  Have each group explain their coordinate system.

    2.  How could your group's coordinate system be improved (made more precise?)

    3.  What characteristics do all of the coordinate systems have in common?

    4.  Which coordinate system is closest in design to the latitude-longitude coordinate system?



    Have students devise a coordinate system for locating objects in the school courtyard. The following day hold a scavenger hunt in which teams are given coordinates and must list objects found at each location.

    New York State Earth Science Standards:

    ST. 1. Mathematics

    Key Idea 1: Abstraction and symbolic representation are used to communicate mathematically.

    ST. 1. Scientific Inquiry

    Key Idea 1: The central purpose of scientific inquiry is to develop explanations of natural phenomena in a continuing, creative process.

    ST. 2. Information Systems

    Key Idea 1: Information technology is used to retrieve, process, and communicate information as a tool to enhance learning.

    ST. 6. Models

    Key Idea 2: Models are simplified representations of objects, structures, or systems used in analysis, explanation, interpretation, or design.