Presenting the task: This assessment is embedded in a context-setting activity introduced by the teacher to the whole class. The context-setting activity takes one class period, and the paired work—the assessment task itself—requires a second class period, possibly spilling over into part of a third.
The following is written as directions to the teacher:
Introduce the activity by telling the students they will be working on estimating the number of buttons in their class today.
Ask students for their estimates of the number of buttons in the class. Give students a few minutes to look around—at their own buttons, at the number of buttons that students near them have—and to discuss their estimates with students near them. Collect some of their estimates and list them on the board.
As students are estimating, some questions and issues will probably arise. Encourage students to talk about any questions that occur to them (for example, ''What about buttons on sweaters or coats hanging in the closet?" "Were there buttons that they didn't notice or forgot about because they were not in obvious places?" "Should the teacher's buttons be included?" The answers to these questions, which can be decided jointly by you and your students, will depend on your particular situation. For instance, if students' outerwear is stored in an inconvenient location you might decide not to include it.)
Now each student should carefully count the number of buttons that he or she has. They might work in pairs or threes to help each other count carefully. Record their data on a line plot so that everyone in the class can see it. For example:
Encourage students to describe these data by asking: "What would you say about the number of buttons in our class?" Students may comment on the range of the data, where data are clumped, for