Below are ideas for extending this topic beyond the activity & exploration which you just completed.

• Lesson Assessment and Answer Key
• Readings: Readings & comprehension questions.
• Activity Extension: Use your cornmeal & salt "land" for other experiments.
• Picture Discussion: This photo will start your class thinking and talking.
• Background information: An online book for teacher & advanced students who want to explore further.

These readings are free with registration on ReadWorks, a nonprofit that provides Common-Core-aligned readings. All readings include comprehension questions.

• Erosion describes how water, ice, and wind can slowly change the land (Grade 2)
• A Grand Old Canyon tells the story of the most famous canyon in the United States—the Grand Canyon (Grade 2)

Here are two more experiments to try with your cornmeal "land."

• Experiment 1: Make different landforms & observe how water changes them
• Experiment 2: Make a meandering river canyon

If you store your cornmeal “land” in a sealed food storage container, it will keep for at least two months without going bad. If it’s soggy, add cornmeal. If it dries out, add water.

Have students work in pairs and use the cornmeal-and-salt “land” to make a landscape of their own design. Ask them to:

• include some high land—a hill or a mountain or a plateau
• include some low areas—valleys or plains or even a cave
• choose where the cup will drip and predict what will happen
• draw a “before” picture
• try the experiment
• document the changes by drawing an “after” picture

Discuss:

How could you make a river that flows across a plate of cornmeal?

If you want to know how we did it at Mystery Science, go to Make a River (part 2).

At Mystery Science, we knew that rivers flow downhill. So we filled a plate with cornmeal, tamping it down so it stayed put. Then we tilted the plate on another plate, and set up our drip stick. Here’s our river.

You can try our method — or make up your own.

Return to Make a River (Part 1).

When it rains here, where will the water go? Do you think the water will change the land? Why do you think that?

For more detailed background information and suggested activities, check out Rocks, Rivers, and the Changing Earth — a first book about geology, available free with registration on Epic!.

The first chapter, Rivers to the Sea, details the steps in a river’s journey, from rain falling in the mountains to the formation of a delta where the river flows into the sea. This is too advanced for most second graders, but great for older students or teachers.