Resumen

This study aimed to examine elementary school children’s performance and strategies when estimating linear measurements. 46 third-graders and 41 fifth-graders were asked to estimate the length of various objects in a series of tasks that looked at units of measurement and task context. The children’s performance was quite poor and was influenced by age. Both age groups gave better length estimates when non-standard units of measurement were used rather than when centimeters (standard units) were used. Significant differences were revealed in estimating objects with different orientations, whereas no differences were found when estimating objects presented in different backgrounds or objects of three dimensions. Unit iteration and use of benchmarks were the most common strategies found, with differences in children’s frequency use, however, depending on the presence of standard or non-standard units of measurement.