Mathematics educators frequently recommend that students use strategies for measurement estimation, such as the reference point or benchmark strategy; however, little is known about the effects of using this strategy on estimation accuracy or representations of standard measurement units. One reason for the paucity of research in this area is that students rarely make use of this strategy spontaneously. In order to boost students' strategy use so that we could investigate the relationships among strategy use, accuracy of students' representations of standard measurement units, and estimation accuracy, 22 third-grade students received instruction on use of the reference point strategy and another 22 third-grade students received instruction on the guess-and-check procedure. Analyses reveal that children's strategy use predicts the accuracy of their representations of standard linear measurement units and their estimates. Relative to students who did not use a reference point, students who used a reference point had more accurate representations of standard units and estimates of length. (Contains 4 tables and 3 footnotes.)