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DescriptionIn the third clip, researcher Amy Martino then worked with Mark and Laura. Mark justified his solution using each model he built. The researcher asked Mark if he thought that a different model might...
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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...
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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 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 second clip, David and Meredith worked on building models to represent their solution to the problem: Which is larger, two thirds or three quarters, and by how much. David first built two...
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DescriptionAmy Martino introduced division of fractions by asking students to describe how many white rods equal an orange and red train. She then asked the students to name the white rod if the orange and red...
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DescriptionIn this short clip, James explains to Robert B. Davis his solution to the problem: Which is larger, one fourth or one ninth, and by how much? After some questioning, he explains that the train (i.e.,...
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DescriptionAmy Martino leads a whole class discussion during which they talk about ways of writing number sentences for two problems: 1) How many one sixths are in one? and 2) How many one twelfths are in one?...
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TitleAlan's Infinity
DescriptionIn this clip from 4th grade classroom study, students discuss the placement of numbers between zero and one on a number line. A debate ensues as to how many numbers exist between zero and one. Andrew...
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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....
