To be able to use the map, it is necessary to know the units Elizabeth and Frank used to measure.

They measured using steps. They also could have measured with standard units of measure like feet or meters.

Frank's wastebasket is 8 steps to the right of and 3 steps in front of Mr. Origin. The coordinates of the wastebasket's location are 8 steps right and 3 steps front. Elizabeth's desk is 3 steps to the right of and 10 steps in front of Mr. Origin. What are the coordinates of Elizabeth's desk?

Mathematicians use pairs of numbers, called coordinates, to give locations. They write them inside parentheses like this:

The wastebasket is at (8, 3).

Elizabeth's desk is at (3, 10).

The pairs of numbers are called ordered pairs because the order in which they are written is very important. The first number always tells the distance to move along the left/right or x-axis. The second number always tells the distance to move along the front/back or y-axis.

Discuss these questions with your class.

  1. How can you describe the location of the globe within the classroom?
  2. Describe the location of the globe using Mr. Origin as a starting point.
  3. Use coordinates to give the location of the globe. What two numbers will you use? In what order?

Use the Practice with Coordinates page in the Student Activity Book to practice locating points on a map.

Play the Find the Panda Game in the Student Activity Book to practice using coordinates to locate an object on a map.