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DescriptionIn the fourth clip Erik repeated the explanation of his model to the classroom teacher. His model consisted of a train of three orange and one dark green rod and lined up four blue rods. He lined up...
11
DescriptionIn the sixth clip Erik and Alan worked on the task: Which is larger, one half or three fourths. Erik showed, using the orange and red train as one, that the difference between the two fractions was...
12
DescriptionIn the first clip a visitor worked with Danielle and Gregory on the second task of comparing two third and one half. Danielle showed her using the twelve-centimeter long model, that three fourths was...
13
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...
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DescriptionIn the fifth clip Michael and Brian extended their model using the orange and red train to show thirds and twelfths in addition to fourths. They showed that the difference between two thirds and three...
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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...
16
DescriptionIn the fourth of five clips from this classroom session, the researcher, Amy Martino, returned to Alan and questioned him about the third model that he had built for finding the difference between one...
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DescriptionIn the fifth of five clips from this classroom session, a visiting researcher asked David, Erik, and Meredith about the large model on the floor, which reflected their attempt to reconstruct the model...
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DescriptionIn the second of five clips from this classroom session, Alan worked alone at his desk on a new task that the researcher, Amy Martino, had posed. He built models to find the difference between one...
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DescriptionIn the third of five clips from this classroom session, David, Erik, and Meredith are building a large model on the floor in an attempt to reconstruct what they had built in a previous session....
