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 second clip, Kimberly and Audra worked together on the task: Which is larger one half or three fourths. Kimberly built a model using an orange and red train, two dark green rods, and four light...
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 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 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...
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...
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...
DescriptionIn the first of three clips from a single class session, the researcher asks the 4th grade students to explain the mathematical task of the previous day when each of the three small groups within the...
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?...
DescriptionAs the students were dispersing after class, David called over researcher Carolyn Maher to share his model. He built a balance beam using one vertical and one horizontal rod, placed two light green...