Teachers' Interpretations of a Linear Equation Regarding Physical Quantities

• In Event: 58.084 - Poster Session 13
  In Poster Session: 58.084-13 - Research in Mathematics Education SIG Poster Session

Abstract

We asked 47 in-service mathematics teachers to produce a story about a relationship between weight and volume that could be represented by the equation y = 3x+5. Two independent judges classified the teachers’ responses for coherence based on dimensional homogeneity, internal consistency, and conformity with the given relation. We found a significant increase in the coherence of teachers’ explanations by the end of the program. Here we focus on issues teachers encounter in interpreting a linear equation in terms of relations among quantities of different kinds. We devote special attention to their explanations of the role of the coefficient 3 in accounting for how a quantity of one kind can be converted into a quantity of another kind.

Authors

• Chunhua Liu, Tufts University

• David W. Carraher, TERC

• Sarah Bray, University of Michigan - Ann Arbor

• Analucia D. Schliemann, Tufts University