Math Investigations

Help with Opening PDF Files

Chapter 24

Part 1: For the problem in the Teacher's Edition, page 614

Provide the students with a copy of the Problem Worksheet (PDF file).

Have the students look at the map on page 614 of the student book. Ask them to think of places in your community of which they would like to make a map. For example, they might suggest a playground, a park, a shopping center, the main section of town, etc. If possible, try to arrange short field trips to the places they choose. This will help them make accurate maps. If field trips are not possible, the students can always make a map of the school playground.

Remind students to label their grids with numbers and to describe each location with ordered pairs.

The grids students create will vary but should look somewhat like the grid on page 614 of the student book.

Part 2: Be an Investigator

A good time to do this investigation is after Lesson 3 on graphing functions.


  • graph paper

Introducing the Investigation

Introduce the investigation by reading aloud the assignment at the top of the first page of the Description of Investigation and Student Report (PDF file), by having one of your students read aloud the assignment, or by having the students read the assignment individually.

Put the students in groups of two to four to work on the investigation.

Doing the Investigation

Help the students get started on this investigation by asking questions such as:

  • What will this graph show? (the price of different numbers of packages of party favors)
  • How can you figure out what some of the coordinates of points on the graph are? (The number of packages is the x-coordinate and the price is the y-coordinate.) Since the price is $2 per package, you multiply the number of packages by the price. So for 3 packages, the coordinate would be (3, 6).

Students who are just learning to graph using coordinates can get confused between the x-coordinate and the y-coordinate. Observe the students as they are creating their graphs so you can straighten out any confusion.


Price of Party Favors - Graph

line drawn through the following points:
(0, 0); (1, 2); (2, 4); (3, 6); (4, 8); (5, 10)

Student Report

The letter back to Ms. Jackson gives the students an opportunity to show what they have done.

Extending the Investigation

Have the students find price information for items in party stores. Have them create graphs to show the prices for different amounts of these items.

Houghton Mifflin Math Grade 4