This fascinating book explains how the shape of Earth is changed by weathering and erosion - the breaking down of rocks and minerals which are then carried from one place to another by water, ice, wind, and gravity. It is this movement that carves out valleys, causes trees to topple over, and creates or destroys good farmland. Examples of changes to landforms help show young readers the effects of weathering and erosion, which can happen quickly or sometimes take centuries! Teacher's guide available.