Now we'll look at how Jesse Solomon's ninth-grade class worked with this problem. Before this class, students had worked on finding patterns, measurement, estimation, and evaluation of algebraic expressions. Most recently, the teacher had introduced the ideas of "one-step" and "two-step" rules. Later in this semester, he will help students relate these concepts to algebraic ideas. The classroom of 17 often works in groups of mixed ability, and they regularly use manipulatives and make presentations on their work and their methods as part of each unit.

Notice both how the teacher sets up the problem and the steps students use to solve it. In particular, focus on strategies and how students create, use, and evaluate strategies.

Read the questions below before you watch the video. Then answer the questions. You may want to watch the video once for each question.

• Do you think these students consider this an engaging problem? Why or why not?
• How does the teacher respond to the wide range of strategies being used as he observes group work?
• The teacher encourages students to collect data first before trying a rule. Why might he do this? How does it effect student problem solving?
• What evidence do you see of student reasoning and self-monitoring in the problem-solving process?

Now watch the video excerpt at left (duration 5:26) of Mr. Solomon's students as they work on the activity.

  Observe a classroom