DescriptionIn the third clip from this session, the class reviewed the problem: Which is bigger, one half and one third, and by how much? Laura and Jessica built a model to show that one half was larger than one third using an orange and red train to represent one, dark green rods to represent one half, and purple rods to represent one third. Audra joined Laura and Jessica to corroborate their findings. When researcher Carolyn Maher asked them what the difference was, Audra placed two white rods next to the purple rod, showing that that train was equal in length to the dark green rod. Jessica placed a red rod next to another purple rod, saying that “It’s a red bigger.” The researcher then asked them what number name they would give to the red rod. Audra and Jessica independently lined up three red rods against the model of the dark green rod and the purple and red train that they had used to compare the two rods, and each stated that the number name would be one third. Kelly agreed with their solution and built a train of two light green rods at the overhead. She then placed a light green rod next to a red rod and said that one half was bigger than one third, indicating that the red rod was one third and the light green rod was one half. Brian first verified that he had heard the first argument correctly and then said that he didn’t agree. He explained that the difference was one sixth since if the thirds were split in half they would become sixths. Brian indicated that the red rod was one half of the purple rod, which would be called one sixth, and that the difference between one half and one third is one sixth. Brian then lined up a purple rod and two red rods and said two red rods equaled one purple rod and therefore would be called one sixth.
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Related Publication Type: Related publication Label: Ed.D. dissertation references the video footage that includes Comparing fractions, a whole class debate, Clip 3 of 5: Brian challenges the girls' argument Date: 2009 Author: Yankelewitz, Dina (Rutgers, the State University of New Jersey)
Related Publication Type: Related publication Label: Ed.D. dissertation references the video footage that includes Comparing fractions, a whole class debate, Clip 3 of 5: Brian challenges the girls' argument Date: 2001 Author: Steencken, Elena Perrone (Rutgers, the State University of New Jersey)