Help with Opening PDF Files

## Chapter 3

### Part 1: For the problem in the Teacher's Edition, page 58

Provide students with the Problem Worksheet (PDF file)

Have students share the different ways they wrote the addition sentences. You might even want to work with the class to list the addition sentences in an organized way to see how many different addition sentences there would be. For example,

 51 + 1 = 52 50 + 2 = 52 49 + 3 = 52 48 + 4 = 52 etc.

 50 + 2 = 52 2 + 50 = 52 25 + 27 = 52 20 + 32 = 52 40 + 12 = 52

There are 51 different ways to write these addition sentences.

### Part 2: Be an Investigator

A good time to do this investigation is after Lesson 7 on subtracting numbers.

#### Introducing the Investigation

Introduce the investigation by reading aloud the assignment at the top of the fist 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 to work on the investigation.

#### Doing the Investigation

Don't expect students to make a drawing to scale. Just make sure they have all of the measurements in their drawings. The numbers across the wall should total 168 inches, the width of the wall.