Friday, November 2, 2012

Interview Report I: Proportional Reasoning

http://www.youtube.com/watch?v=R3CBuLv72kw&feature=youtu.be


Background Information
            The student I interviewed is currently a 9th grader who is taking geometry. The student is from my focus class, so from my observation, I know that he has a good background in mathematics. His math teacher is Ms. Mendez, which is my cooperating teacher (CT). The child is 14 years old. In the interview, I was supposed to chain up the paper clips when I do the demonstration of using the big paper clips to measure Mr. Short. However, I decided to draw a hat on top of Mr. Short to make sure that 4 big paper clips will be the size of him without being chained because I did not want the student to waste time to chain the paper clips. The theory and activity remained the same to a certain extent.

Proportional Reasoning
                Proportional reasoning involved comparison of two or more extensive measures. For example, when Lamon (1993) talked about the associated sets, he talked about using pizza to teach the students about proportion reasoning. The pizza question asked, “The student is shown a picture of 7 girls with 3 pizzas and 3 boys with 1 pizza. Who gets more pizza, the girls or the boys?” (p. 5). These kinds of questions can help students think critically while figuring out an answer because it requires understanding of proportional reasoning. Lamon (1993) claimed, “Proportional reasoning was said to occur when a student could demonstrate understanding of the equivalence of appropriate scalar ratios and the invariance of the function ratio between to measures spaces, whether or not the student could represent these relationship symbolically.” When the pizza question was being asked to the girl, the girl provided a logistic explanation. However, this would not make sense if the student uses math symbols to symbolize her words. But the key point in proportional reasoning is that the students have to use clear explanation to show their understanding of the question instead of answering the question using procedural method.

            A student is using proportional reasoning when the student can provide accurate calculation to the problem. Furthermore, the student should also be able to explain what he or she is doing in the problem. By just computing the answer, the student shows that he has strong procedural skills, such as computing, seeing patterns, and etc. In addition, if the student is able to explain his or her answer with good reasoning and logic, then it shows that the student is having some sort of conceptual understanding in proportional reasoning. In proportional reasoning, conceptual understanding is far more important than procedural fluency because they have to be able to understand the concept in order to have good reasoning.

            Through the interview, I was not able to see that the student has much proportional reasoning because he simply did not use anything related to ratios. However, the student was at the pre-Proportional Reasoning Stage. Lowery (1974) claimed, “A student is at the pre-Proportional Reasoning Stage of development if his or her explanation refers to estimates, guesses, appearance, or extraneous factors without using the data of if he or she uses the data in an illogical way” (p.18). The student told me that the answer is “eight” because he simply added 2 small paper clips to find Mr. Tall’s height when Mr. Short is 6 small paper clips. The student is having his own guesses and reasoning to figure out the answer, but it shows no proficient level of proportional reasoning ability. Furthermore, this is an illogical way to use the data. However, the student does tend to use the most obvious solution to answer the question. Hence, the student used the additive property instead of using proportional reasoning to solve the problem.

Next Step 
            As the interview assignment mentioned, students usually do not master proportional reasoning until they are 16-18. My student was 14 years old, so it makes sense that he might be a little confused with problems like that. If I was teaching the student’s class, I believed that I would need to introduce the topic proportional reasoning starting from the beginning because it seemed like the student did not have much experience in proportional reasoning back in middle school. I would not use textbooks to teach the students proportional reasoning because it’s simply too procedural. Cramer et al. (1993) claimed, “Proportional reasoning abilities are more involved than textbooks would suggest” (p. 169). Textbook would not be able to teach students proportional reasoning ability, instead I would start off by providing hands-on activities to the class to get the students engaged, so they will be willing to learn proportional reasoning.

            My activity can simply consist of coins of dimes and quarters. Since most students use money in a daily basis, they would find this activity relates to them, so they are more likely to be engaged in this activity. They would also like to play with money, since everyone likes money. Using coins, the students will see the ratio 2:5, which means every 2 quarters is the same as 5 dimes in terms of values. By giving out this activity and providing proper scaffolds to the students, the students will have an early foundation of proportional reasoning.

Reactions

            I actually interviewed two students from the same classes at a different time, and I learned that they made the same mistakes. Both of my students gave me the answer 8 because they thought you are supposed to add 2 instead of using proportional reasoning. Surprisingly, they were also some of my top students in the class, so I thought they would be able to answer my question. This makes me wonder did they learn proportional reasoning back in middle school. Was the teacher in their middle school unqualified to teach proportional reasoning? Was this the reason why students did not master the topic proportional reasoning? Hence, I believe that it is necessary to reteach proportional reasoning in high school, so that students can become proficient in proportional reasoning.


Works Cited

Cramer, K., Post, T., Currier, S. (1993). Learning and teaching ratio and proportion: Research implications. In D. Owens (Ed.) Research ideas for the classroom: Middle grades mathematics. NY, NY: Macmillan Publishing Company.
Lamon (1993) Ratio and Proportion: Connecting content and children’s thinking. Journal for Research in Mathematics Education, Vol. 24(1), 41-61)
Lowery, L. (1974). Proportional Reasoning. In Learning About Learning Series. Berkeley, CA Univ. Of California, pages 17-20 and 37-38

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