ELEMENTARY STUDENTS CONSTRUCTION AND COORDINATION OF UNITS IN AN AREASETTING

Much of students' numeric mathematical activity can be interpreted as the construction and coordination of units. This article reports evide nce of construction and coordination of units in a measurement setting , using data gathered from 4 students during individual problem-solvin g sessions near the end of their fourth-grade year and augmented throu gh knowledge gained with these students in the previous 2 years. Three students each developed different ways of solving the measurement tas k that reflected the construction and coordination of abstract units, whereas a fourth student did not. On the basis of this evidence we pro pose 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.