In this clip, the first of five clips from a single class session, the researcher asks the students to review how they were able to show that 1/4 is larger than 1/9 by 5/36. The students had worked on this problem in the previous session when they were asked to share a candy bar equally among the students in their group. Two groups were composed of eight students while another was composed of nine students, and their task had been to determine how much more candy each person in the smaller

more »

... would receive than those in the larger group. After James explains his recollection of the solution, the researcher asks the students to recall and discuss their original conjecture which had been that the difference between 1/4 and 1/9 was 1/5. Brian and Meredith discuss the thinking which had led to this conclusion, and under the researcher's guidance the class discusses how addition over whole numbers seems to differ from addition over fractions. Problem statement: If the members of one group each received 1 and 1/4 pieces of candy and the members of a second group each receuved 1 and 1/9 pieces, who received more candy and how much more? What is the difference between 1/4 and 1/9?