Show students a brief video of wind moving across sand dunes or of the movement of pebbles underwater in a stream or river. Ask students to describe what they notice in these videos. Student responses should describe that smaller objects like grains of sand or small shells move more easily and further than larger objects like big rocks. They should also notice that when the objects come up against a barrier, the objects tend to collect in one place. Students may notice that the sand on a beach piles up against a fence or they may notice that the pebbles in a stream continue to flow downriver. They may also notice that the movement of the water in the river is making some of the rocks or soil on the edges of the riverbank fall into the water, changing the shape of the riverbank. This standard is intended to introduce students to the concept of erosion without applying the terminology. The goal is to provide a common experience so that all students have the background needed to discuss weathering and erosion in later grades. 

If a water table is available, students may use it to design their own hands-on investigation exploring the impact of wind and water on soil and rock particles.

This student expectation is an introduction to erosion and how that process changes Earth's surface, which is further explored in grades 3 and 4. In grade 5, students will learn how changes to Earth's surface result in landforms. At this grade level, students are gaining the experiences and conceptual knowledge necessary to understand the movement of rock and soil particles through forces caused by wind and water.