Discussing Strategies

  • 4.6.2 Discussing Strategies

    Grade: PreK to 2nd

    The students work in groups to share their ideas and reach a reasoned consensus about their estimates


    Video Transcript

    ----- Transcript Begins ------
    Teacher narration: The children naturally know that
    they have to reach consensus, whenever they are
    working in a group. They have to work things out
    and everybody has to feel like they came out with a
    part of the answer.
    Girl 2: I'll just say one and a half.
    Teacher: How do you think you'll figure out how
    many scoops are in here?
    Boy 4: Well, there's three already.
    Teacher: Um huh.
    Boy 4: And so it might be like six or something
    like eight or six.
    Teacher: And how can you figure out if there are
    eight or six?
    Boy 4: Because there is already three in there
    and there is not much room and there is not going
    to be like fifteen or twenty-two or something.
    Teacher: Okay, so there is not much room left?
    Boy 4: No.
    Teacher: You know there are three in this much.
    Boy 4: Yah.
    Boy 5: But what I am asking is if, um, nine was
    because see three, six, nine.
    Teacher: Okay, so you actually measured it with
    your fingers to see how much would be left?
    Boy 5: Yah.
    Teacher: That's a good strategy.
    Boy 5: So I said nine or ten.
    ------ Transcript Ends -----


    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?



    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.

    Objectives and Standards

    NCTM Standards and Expectations
    • Understand that by similarity, side ratios in right triangles are properties of the angles in the triangle, leading to definitions of trigonometric ratios for acute angles.
    • Apply geometric concepts in modeling situations
    • Pre-K - 2
    • Data Analysis and Probability
    • Geometry
    • Measurement
    • Number and Operations
    • Pre-K to 2nd