This curriculum guide for grades K-6 was prepared to assist teachers and students in learning about the metric system. An introductory section presents a brief history of the metric system and the rationale for introducing it into the schools. Instructional objectives and suggested learning activities are presented for each grade level. The activities vary in format, and sometimes include objectives and followup as well as materials required and procedures. Sample activities include using measuring wheels; weighing snow; using scales, bar graphs, and the Celsius thermometer; and constructing a quadrate out of doors. A short section illustrates how the metric system can be taught at the junior and senior high levels. Background and reference materials for the teacher in the intermediate grades are provided and include tables, charts, and conversion data. A list of references used in preparing the guide is appended. (RG)