DescriptionDuring this clip, the students discuss a task that had been posed by Erik: If I call the blue rod one, what rod will I call one half? A lively discussion centering on the definition of one half...
DescriptionResearcher Carolyn Maher leads a whole class discussion after the students' exploration of the problem: Which is larger, one fourth or one ninth, and by how much? Several students described their...
DescriptionIn the fourth clip Michael and Brian worked together to compare one half and three fourths.
Michael built a model of an orange and red train, two dark green rods, and four light green rods. He then...
DescriptionIn the fifth and final clip from this session, researcher Carolyn Maher asked Jessica to re-explain her original model. Jessica restated her argument, saying that the model showed that one half was...
DescriptionIn the third clip researcher Carolyn Maher asked David to share the theory that he had formulated with the class. David, with some assistance from Erik, said that Meredith had originally built a model...
DescriptionDuring this session, researcher Carolyn Maher provided the students an opportunity to revisit the task that they had been introduced to during the previous session: Which is larger, two thirds or...
DescriptionIn the third clip David, Meredith, Erik, and Alan worked to build models on the floor using rods. David built a model to test his conjecture, while Erik continued working on the thirty-six centimeter...
DescriptionIn the first of five clips from this classroom session, the researcher, Amy Martino, provided the students with an opportunity to briefly discuss a task that they had been working on during the...
DescriptionIn the second clip, researcher Carolyn Maher asked the students what the model that was next in size would look like. Brian said that it would equal the length of twenty-four white rods. The...
DescriptionAmy Martino began the session by asking the students to discuss the task that they had worked on during the previous two sessions: Which is larger, two thirds or three fourths, and by how much?...