The non-italicized font represents additional information included to support the teacher’s understanding of the content being introduced within the CELL.

ANALYZE IT

Note: When students have finished all four Trials, they should determine the mass of sand found in the container in each Trial. Students should use the data from each Trial in Table A to subtract the mass of the container from the combined masses of the sand and the container.

Instruct students to complete the Analysis Questions in their SDRs then discuss them as a class. Use the suggested responses below to guide students’ answers.

Note: Students should compare the data from Trials 1 and 2 in Table A to answer the following questions.

• In which Trial was more sand eroded by the water? More sand was eroded by the water in Trial 2.

• In which Trial was the slope steeper? The slope was steeper in Trial 2.

• What is the relationship between the amount of erosion and the steepness of the slope? The amount of erosion increases as the steepness of the slope increases.

Note: Students should compare the data from Trials 2 and 3 in Table A to answer the following questions.

• In which Trial was more sand eroded by the water? More sand was eroded by the water in Trial 2.

• In which Trial were there obstacles to the water flow? In Trial 3 there were obstacles to the water flow.

• What is the relationship between the amount of erosion and obstacles to the flow of water? The amount of erosion is decreased when there are obstacles to the flow of water.

• Why do you think that obstacles decrease erosion? Obstacles decrease erosion by slowing the flow of water and by catching and preventing soil from flowing down a slope.

Note: Students should compare the data from Trials 2 and 4 in Table A to answer the following questions.

• In which Trial was more sand eroded by the water? More sand was eroded by the water in Trial 2.

• In which Trial was there vegetation on the slope? There was vegetation on the slope in Trial 4.

• What is the relationship between the amount of erosion and vegetation on a slope? The amount of erosion is decreased when there is vegetation on a slope.

• Why do you think that vegetation decreases erosion? Vegetation decreases erosion by slowing the flow of water and by catching and preventing soil from flowing down a slope.

• What parts of a tree do you think help decrease erosion? The roots and the trunk help decrease erosion.

GET FOCUSED

Instruct students to complete the Focus Questions in their SDRs then discuss them as a class. Use the suggested responses below to guide students’ answers.

• What occurs when erosion takes place? When erosion takes place, soil is moved from one location to another. If erosion occurs on a slope, the soil will be washed down the slope.

• What factors increase or decrease erosion? Soil from a steep slope will be eroded more than the soil from a less steep slope. Obstacles such as rocks and vegetation will decrease the erosion of soil from the slope.