Friday, November 2, 2012

Interview Report: Proportional Reasoning

http://youtu.be/HBGTrxtSTQs

Interview Report: Proportional Reasoning
Name: Emma Shrank
Age: 11 years old
Grade: 6th
Subject: Pre-Algebra
Teacher: Molly O’Neil
Pertinent Information: Child’s mother is a UCSC professor

            In the interview, Emma works on the Mr. Tall and Mr. Short proportional reasoning problem. Emma refers a lot to the paper clips because the paper clips gives her a better representation of the problem. Emma arranges the paper clips in a way that measures Mr. Short’s height by positioning one end of the paperclip after another end until enough paper clips cover the height of Mr. Short. The paper clips are the hands-on tool Emma uses to communicate her thoughts along with verbal communication. It helps her quantify what the information given in the proportional reasoning problem.
            During the interview, I notice that Emma understands the problem and knows how to do it. To be certain of her knowledge and to test her knowledge about the question, I take the paper clips away so that she can give me a verbal explanation of her reasoning. Without the use of paper clips or any objects to help her think, I am getting the purest form of what Emma knows. The explanation she gives is based on the paper clips because Emma needs something solid to base her theories and opinions and in this case, paper clips are the objects that solidify her thinking.
            The explanation consists of Emma adding two feet (biggies) to Mr. Tall’s height and her adding three smallies to match the addition of two biggies. As you can see, she uses an additive relation to think proportionally. Although this method works, it only works well with cases that deal with small numbers and not big numbers. In an attempt to squeeze more thought out of her, I try to get her to provide some form of formula for figuring out Mr. Tall’s height given Mr. Short’s height in a general case. Although it is not in the video, she explains to me that she keeps adding to determine Mr. Tall’s height. Procedurally she shows proportional reasoning, but when asked for a general formula, she conceptually does not know two biggies equal three smallies. Emma sees the relationship of for every two biggies added to Mr. Tall, then there are three smallies added as well. The only thing she is missing is that she does not have a strong connection to see both numbers as a fraction or percent. Building the connection between ratios and fractions or percent will be one of the next steps to do with students like Emma learning proportional reasoning.
            My reaction is that she is very dependent on objects and is a student that learns from doing rather than seeing and listening. Emma is a very capable student who knows how to do the proportional reasoning problem. What surprise me is that Emma notice that for every two biggies there are three smallies, but when asked for the general case, she could not produce the same result. I learn that Emma has some background about proportions because she is able to do the problem flawlessly without error. As a result from seeing Emma’s dependence on paper clips, it definitely shows me that most students may rely on concrete objects to get an understanding of proportional reasoning. This can also be applied to other topics in math at the high school and middle school level. A follow up for this lesson is for students to create their own word problems after doing several proportional reasoning problems. I will have students work in groups and come up with one word problem where they show various methods on how to solve it such as paper clips or other objects that help unitize.

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