Students' Proportion Problem Solving with Different Units Coordination Stages

Abstract

The aim of this study is to analyze students’ units-coordinating activities and operations in their proportion problem solving, and to investigate how quantitative structures corresponding to ratios are constructed with different levels of units coordination. As a result of our clinical interviews with three seventh grade students who were at units coordination stage 2 and 3, we found that the use of operations relevant to whole number division was crucial to solving mixed-juice problems and only the stage 3 students assimilated the problem situations involving ratios as three-levels-of-units structures consisting of composite units of indefinite numerosity. Given the importance of units coordination in solving proportion problems, implications for further research are discussed.

Keywords

• proportionality
• ratio
• units coordination stage
• multiplicative reasoning
• whole number division