Sorting Shells

Engage

10 minutes

Show one shell to the students, and have them use as many describing words as they can to tell about that shell. Show another shell and ask: “How are they different?” “How are they the same?”
Next, show the students a shell collection with a larger variety of shells. The collection should include univalve and bivalve shells. Ask children: What do you know about shells? Record their ideas on a chart. Read the book Seashells by the Seashore by Marianne Berkes.

Explore

15 minutes

Place the shell collection where everyone can see it. Make two circles with the yarn loops. Tell students you are going to play a sorting game with the shells. Decide together on two properties, one for each circle. For example, the properties chosen might be “white” and “rough.”

Start the game with three shells for examples. Begin by selecting one shell to look at closely. Place it in a yarn circle based on a specific characteristic (for example, white). Hold up the next shell while talking out loud about its characteristics and where you will place it (for example, rough). Continue with the last example shell, using an example that could have both characteristics (it might be rough but is also white). Students will choose where to put that shell. Some students may be ready to consider more than one attribute at a time, and if this is the case you may want to move the yarn and create a Venn diagram. You could also show a shell that is neither white nor rough, and see what students want to do with it.

Encourage each student to place their “own” shell based on the main characteristic of white or rough. After all the shells have been sorted, hold up one last shell and ask the group to point where that shell belongs (in which group).

Explain

20 minutes

When all the shells have been sorted, ask students: What did you notice about the shells in this group? How are they all alike? How are they different? How about the other group? Encourage students to talk about new ways the shells can be sorted. Using the shell property word chart, have students describe new yarn loop groups they could create for different characteristics. Introduce the idea of overlapping yarn loops (Venn diagram) now, if it was not considered previously. Encourage students in the use of the Venn diagram as they continue to try new ways to sort shells. Create a classroom center where children can continue to practice sorting.

Elaborate

30 Minutes

After children have had experiences with sorting and thinking about different ways to describe their shells, they can solve problems using strategies for sorting.For example: Sally had 12 shells in her collection. How could Sally sort her shells three or more different ways?

Have children draw on a piece of paper, using pictures, diagrams, and words to describe their thinking. After children have finished their work, come back together as a whole group and share thinking. Children will learn from each other as they listen to different ideas.

Evaluate

Use the Shell Sort Levels of Understanding Continuum to assess students’ ability to sort.