In Grade 4 Curriculum:

1. Under Foot:  Investigation 1.1

What are some different kinds of earth materials?

4. Make meaning

Discussion 10 Mins

Purpose of the discussion

The purpose of the discussion is to consolidate students' growing awareness of the natural earth materials. Return to the investigation question for the discussion.

Engage students in the focus question

Remind students of the investigation question.

What are some different kinds of earth materials?

Now that students have explored some earth materials, are they convinced that everything on the class list is an earth material, a part of the natural earth? Do they have new things to add, as a result of having explored some earth materials? Are there things they think should be removed from the list?

Return to any challenges students may have posed as the class developed the list, regarding the inclusion of manufactured objects (e.g., buttons, concrete) or living animals or plants. If no one has questioned the inclusion of these on the list, do so now. For example:

There is something about the [living thing mentioned] that seems different than the materials you just explored in your small groups, and different than most of the things you have added to the list. What do others think about including [living thing(s)] along with the rocks, gravel, and other things on the list?

If there are several living things on the list (e.g., grass, worms, small mammals), include them as a group.

Listen as students share their thoughts and ask them to explain the reasoning behind their thinking. Through this process they may come to the conclusion that earth materials should not include living things or manufactured objects.

Share the scientists' definition

Explain that scientists have also thought about this same question, and have decided that earth materials include the natural materials that are not alive and that have not been manufactured by humans (so, no concrete or buttons that we may find beneath our feet). After living animals and plants have died and have started to decay, scientists do consider them to be earth materials. So pieces of dead insects, dead leaves and pieces of wood, are included along with water, rocks, sand, gravel, and other natural earth materials.

Students are likely to have suggested "dirt" as an earth material. Now is the time to replace the term "dirt" with the term "soil", explaining that this is the term that scientists use.

Summarize the discussion and recap the investigation

Students’ responses to the questions below will serve as a summary.

  • What do you know now about earth materials that you didn't know before?
  • What did you learn today that surprised you?

Acknowledge that students have refined a list of earth materials, and have started to investigate eight of those materials: pebbles, gravel, sand, clay, shells, organic soil, water, and oil. Explain they will continue to investigate these eight materials and some new ones in the upcoming weeks.

Students have also started to record information called data in their science notebooks. Those notebooks will be an important part of the science unit over the next several weeks.