Engage: Nails, Bolts, Screws

Introduction to Classification

Use this simple hands-on sorting activity to initiate a discussion of how and why we classify soils.

Step 1. Provide each student or team of students a small container of common metal household fasteners (e.g. wood screws, metal screws, nails, bolts, tacks, paper clips, pins, etc.). See the photo right for an example.

Step 2. Ask students to sort the fasteners into groups based on the characteristics that they observe.

Allow student teams to work for 5-10 minutes sorting and discussing their criteria. When they appear to have created clusters of like items, stop the sorting and ask the following questions:

• What were your criteria for separating the objects?
• Do you see additional ways that you might separate the objects? (e.g. color, length, materials)
• What purpose might you find in sorting objects? (storage, use, value, rarity)
• Do the objects have different characteristics that could define their use?

Time required: 20 minutes to sort and conduct discussion. As an alternative, educators can share the images on screen and ask the questions.