Two instructional approaches and a control group were used in this study. Metric instruction in a college introductory physical science course was divided between: a) Approach A in which volume instruction followed that of length and area; b) Approach B in which volume was stressed but area was not introduced; and Approach C, the control (no instruction in metrics). Subjects in Approach B achieved significantly greater than did students in either Approaches A or C on a metric volume test. (CP)