A case study on the quadratic function problem solving process of middle school students with different unit coordination stages

Jin Ah Lee1   Soo Jin Lee2,*   

1Teacher, Gwanggyo Middle School
2Professor, Korea National University of Education

Abstract

The purpose of the current study is to report a part of our larger project whose focus is to understand a relationship between students’ units coordination and K-12 school mathematics. In particular, in this paper we report how students who exhibit distinct levels of units coordinations used their knowledge of proportion to solve quadratic function problems of the form . To this end, three 7th grade students all of whom assimiliated whole number problem situations with three levels of units but showed different levels for fraction problems were chosen. We carried out clinical interviews not only to understand their ability to coordinate units but to understand their problem solving process of proportion and the quadratic function problems. The analysis suggest that their abilities to coordinate units influenced their ways to solving proportion problems, and in turn influenced their ways to solve the specific form of quadratic functions. We have finalized our study by discussing how students’ ability to construct and coordinate units, their proportion knowledge, and their knowledge associated with expressing the specific type of quadractic functions could be related.

Figures & Tables

Figure 1.Two perspectives on the missing value problem situation using proportional relations (Carney et al., 2015, p.142).