DescriptionIn the second clip, researcher Carolyn Maher asked the students to build a model to show which is bigger, two thirds or one half, and by how much. The students worked with their partners to solve the...
DescriptionIn the seventh clip, Erik and Alan worked to extend their model using the orange and red train to show fourths and halves. They concluded that three fourths was larger than two thirds by one twelfth....
DescriptionIn the fourth clip, researcher Alice Alston worked with Gregory and Danielle on the task: Which is larger two thirds or one half and by how much? Danielle built two models, one using the dark green...
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...
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...
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...
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...
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...
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 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...