We suggest students work in pairs. Homeschool students can work alone.

Students will need to cover their workspaces with plastic trash bags or table covers. Alternatively, students can work outside when they are spraying their paper mountains with water.

If students want to keep their models, be sure to give the models time to dry.

We suggest students work in groups of four. Homeschool students can work alone.

Prepare “Paper Boulders”

Cut or tear each sheet of construction paper into about 12 pieces. We used a paper cutter to cut many sheets at the same time, making irregularly shaped pieces, but tearing or cutting with scissors will also work.

Each group (or single homeschool student) should start with 3 sheets worth of boulders (about 36). We recommend providing plenty of boulders at the beginning so that the students will still have large boulders at the end of the activity. That way, students will be able to see how the sizes of the rocks change as they move downstream.

We suggest students work in pairs. Homeschool students can work on their own.

You will need access to water for this activity.

Students will need to cover their workspaces with a table covering (e.g., trash bag) in case of spills.

We suggest students work in pairs and share materials with another pair of students at the same table cluster. Homeschool students can work on their own.

Prepare the Cornmeal “Land" and "Drip Sticks" Before Class

For each group of four students, you’ll need to prepare a container of cornmeal “land." For each pair of students, you'll need to prepare a "drip stick." This will take about 15 minutes. You need a pushpin, a permanent marker, a mixing bowl, and a measuring cup. Here are instructions.

Fill Solo Cups with Water

Two Solo cups will be used to support each pair's "drip stick" apparatus. For each pair of students, fill another Solo cup about halfway with water.

Organize Materials for Distribution

We suggest that you create supply distribution stations for students. In the first part of the activity, students will need the following supplies:

After students set up their cornmeal “land,” students will need the following additional materials:

Save Materials for the Next Lesson

If you plan to teach the next lesson in this unit:

• Save your cornmeal "land." Pour it back into the food storage containers and keep them covered until you teach the next lesson.
• Save your "drip sticks."
• Save the plastic plates and all the Solo cups.

You will need access to water for this activity.

Students will need to cover their workspaces with a table covering (e.g., trash bag) in case of spills.

We suggest students work in pairs and share materials with another pair of students at the same table. Homeschool students can work on their own.

Prepare the Cornmeal “Land” and “Drip Sticks” Before Class

For each group of four students, you’ll need a container of the cornmeal “land” that you made for Lesson 3. Each pair of students will also need a “drip stick" that you made for Lesson 3. (If you have not taught Lesson 3, you will need to make cornmeal “land” and "drip sticks." Here’s how .)

Prepare Aluminum Foil and Paper Towel Strips

Each pair of students will need two small squares of aluminum foil (about 1½” squares), and four paper towel strips (each strip should be about 1” x 5”).

Organize Materials for Distribution

We suggest that you create supply distribution stations for students. In the first part of the activity, each student will need the following supplies:

In the second part of the activity, students will work in pairs to protect their cornmeal hill from erosion. To create their erosion protectors, each pair of students will need the following additional materials:

In the third part of the activity, students use "drip sticks" to create rainstorms over their cornmeal hills. Each pair of students will need the following additional materials: