Math Investigations

Help with Opening PDF Files

Chapter 9

Part 1: For the activity in the Teacher's Edition, page 230

Provide students with a copy of the Activity Page (PDF file).

The following questions may be used to help your students get started.

  • What operation will you use in each table? (multiplication)
  • What number will you multiply by in the table for the least number of eggs? (2)
  • What number will you multiply by in the table for the greatest number of eggs? (4)

Answer:
Table for the least number of eggs:

Rule: Multiply by 2
Input Output
3 6
5 10
7 14
9 18

Table for the greatest number of eggs

Rule: Multiply by 4
Input Output
3 12
5 20
7 28
9 36

Part 2: Be an Investigator

A good time to do this investigation is after Lesson 5 on multiplying with eight.

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

Doing the Investigation

When students have completed the investigation ask them why the longest frog does not have the longest jump. In the discussion bring out the fact that although Ferdinand is 3 inches long, 2 inches shorter than Flo, he can jump eight times his body length. When you do all of the multiplication, Ferdinand jumps farther than any other frog.

Answers:

Name of Frog Length of Frog Length of Jump Length of Jump in Inches
Fanny 1 inch 5 times its body length 5 inches
Flo 5 inches 3 times its body length 15 inches
Ferdinand 3 inches 8 times its body length 24 inches
Fred 2 inches 3 times its body length 6 inches
Fiona 4 inches 5 times its body length 20 inches

The frogs in order of body length from shortest to longest are           Fanny, Fred, Ferdinand, Fiona, Flo.          

The frogs in order of length of jump from shortest to longest are           Fanny, Fred, Flo, Fiona, Ferdinand.          

I think           Ferdinand            will win the contest because           Ferdinand has the longest jump.           

Student Report

The letter back to James Hwang gives students an opportunity to show what they have done and explain their thinking.


Houghton Mifflin Math Grade 3