Purpose of the discussion

The purpose of the discussion is to consolidate students’ understanding of the terms “property,” “similarity,” and “difference”.

Engage students in the focus question

Ask students if they think they have information to help answer the investigation question:

Suggest that students look for properties that are listed under two or more materials. Some possible findings:

• Aluminum and nylon are both smooth.
• Pine and oak both have stripes, or show the grain typical of wood, but none of the other materials do.
• Wood, pine, and aluminum are not shiny but the other materials are shiny.
• Steel feels cold but none of the other materials do.
• The materials have different colors.
• Steel seems hard when I tap on it, but pine does not.
• Acrylic is the only transparent material.
• Steel and copper are heavier for size than pine or oak.

Summarize with the following:

• How do properties of materials help us to think about how pine and aluminum are alike and different?

Tell students that they will continue to work with these cubes of materials for several more weeks, and that they will discover more about their properties. Make a copy of the class table on a large sheet of paper and save it so students can add more information as they go along.