E-Example 4.6.1: Developing Estimation Strategies by Making Connections

Developing Estimation Strategies by Making Connections among Number, Geometry, Measurement, and Data Concepts: Estimating Scoops

Estimating Scoops

Estimation activities encourage students to make connections among the mathematics concepts they are learning and the skills they are developing. In this multipart video example, the class discussions and the decisions the teacher makes contribute to students' opportunities to connect their understandings of number, measurement, geometry, and data in order to make estimates. Purposeful activities together with skillful questioning by the teacher can help students understand relationships among mathematical ideas, as described in the Connections Standard. In this first part, Estimating Scoops, the teacher presents an estimation task (estimate the number of scoops of cranberries in a jar) to the second-grade students and talks about the teaching decisions she is making. In the second part, Discussing Strategies, the students work in groups to share their ideas and reach a reasoned consensus about their estimates. In the third part, Estimating Cranberries, the students estimate the number of cranberries rather than the number of scoops.

Video Segments

The class in these video segments is engaged in the estimation and analysis of data centered first on the number of scoops of cranberries to fill a jar and then on the number of cranberries to fill the jar. In this segment, each student makes an estimate of the number of scoops and then the class organizes their collective estimates in a meaningful way.

Consider what mathematical concepts these students are using. How is their thinking encouraged, and how else could it be encouraged?

Teachers plan lessons, encourage working groups, and guide class discussions, all of which influence the extent to which students are likely to make connections among the many mathematical concepts they are learning. Throughout this video example, the teacher talks about her decisions as the students are making estimates and collecting and interpreting data. What do you notice about how the teacher interacts with the students in the activity?

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Video Transcript
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Video Transcript
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Discussion

Keeping each student's attention during whole-group discussions is often difficult in prekindergarten through grade 2 classrooms unless the students are involved in the activity. The teacher of the second-grade class shown in the video is using locally grown cranberries as a physical material for helping students develop estimation skills. The activity involves much more than students' looking at a jar of cranberries and a scoop to make their estimates. The teacher helps the students examine their estimates using the graph they create. Then (not shown in these video clips) the teacher and students discuss the range of responses (from 5 to 22) and the mode, the number named most frequently. In this way, she takes advantage of a teachable moment to introduce the concept of mode.

Take Time to Reflect

What do you observe about the students in this brief video that might influence the decisions the teacher makes as she introduces this lesson?
How does the process for creating a graph shown in the video facilitate the students' understanding of their data?
In what ways does the teacher involve all students?

Video Credit

Roche, Robert . "Cranberry Estimation." In Estimating produced by WGBH Boston. Teaching Math, A Video Library, K–4. Funded and distributed by the Annenberg/CPB Math and Science Project, P.O. Box 2345, S. Burlington, VT 05407-2345, 1-800-LEARNER.

Estimating Scoops

Discussing Strategies

Estimating Cranberries