Each group must have a small sample of each kind of soil. Have these samples set up before you begin instruction. Ask students why they look different. Have students feel the three types and contrast the three. Label one pile as sandy.
Sandy soils contain mostly sand.
Sandy soils do not hold water very well. Most sand is small pieces of quartz. Another pile of soil will be labeled as clay. Clay soil is mostly clay and is made mostly of small pieces of mineral other than quartz. Clay soil holds water very well.