Elementary Students' Construction and Coordination of Units in an Area Setting

Abstract

Much of students' numeric mathematical activity can be interpreted as the construction and coordination of units. This article reports evidence of construction and coordination of units in a measurement setting, using data gathered from 4 students during individual problem-solving sessions near the end of their fourth-grade year and augmented through knowledge gained with these students in the previous 2 years. Three students each developed different ways of solving the measurement task that reflected the construction and coordination of abstract units, whereas a fourth student did not. On the basis of this evidence we propose that the task of measuring 2-dimensional regions becomes possible when a student is able to construct iterable 2-dimensional units and coordinate those units.