Home  ## This webpage facilitate opportunities for researchers, administrators, and practicing school professionals throughout the region to exchange ideas for mathematics teachers professionalization using Lesson Study. ## Speed 4

Title Speed 4  1 Takeo Takahashi 2013.09.06 Koganei Elementary School attached to Tokyo Gakugei University Takeo Takahashi Elementary School G-6（12 years old） In this lesson, the teacher poses the problem "A first grade student runs 40m in 8 seconds, and a sixth grade student runs 100m in 16 seconds. In 120 meters sprint, how many meters ahead should one-year student start?" Students solve this problem by using the number line, and proportional relationship between time and distance. Later in the lesson, a student proposes making the distance of the sixth grade student longer instead of to making the distance of first grade student shorter. Then students discuss if this solution would work. (46:44) You need Facebook account to show rating and accept"Join Rating IMPULS". 0% （0 people /0people voted "like it"）
Introduction/Posing Problem Solving Problem/List answers The teacher places a table that shows a first grade student runs 40m in 8 seconds and sixth grade student runs 100m in 16 seconds on the blackboard. At first, the teacher asks the students which one is faster. Students determine sixth grade student is faster. After that, the teacher poses following problem. "We want to make this two students finish at the same time. The distance is 120m, and they start at the same time. How many meters ahead should the first grade student start?" (6:31) After the teacher poses the problem, he has students work independently for 9 minutes. After the individual work, he asks students for their answers. The teacher lists these answers on the blackboard. (4:26) The teacher asks the student who gave 24m as an answer how to solve the problem. The student explains that she found the time that that a sixth grade student would need 96/5 sec to run 120 m, and also the speed of the first grade student. Then she calculated the speed of the first grader. Then she calculated the distance the first grader would run in 96/5 sec and subtracted that from 120m. (5:23) The teacher asks if they want to add anything. One student says she drew her arrow for the 1st grader going backwards from the end. (2:26) One student explains that she found the answer by using a proportional distance and time for both the 1st and 6th graders. (6:10) The student says his idea was based on lengthening the distance of the 6th grade student. (2:28) The teacher and the students discuss if the approach of lengthening the 6th grader's distance would work.. (4:05) The teacher asks the students if they could verify whether the lengthening method would work or not. One student explains that he calculated the time of the 1st grader for 120m and of the 6th grader for 150m, and found they're same. (1:44) One student expresses his idea of finding the speed difference between the 6th and 1st graders, then multiply it by seconds to find the difference in the distances. (5:34)  ## Lesson Study Library

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