The purpose of this work text is to familiarize the elementary school teacher with the metric system. It can be used as a supplementary textbook in methods courses or as the basic textbook for workshops. The decimal system of numbers, metric measurement, measurement in general, and errors of measurement are discussed. Activities for measuring or estimating measurements of physical things using metric units, concrete applications, and opportunities for symbolic problem solving are included. The activities involve expressing equivalent metric measurements using different metric units as opposed to converting from the customary units to the metric units. The metric units covered are length, area, capacity, mass, and temperature. Teaching strategy, classroom management, and student evaluation are discussed. Also included are sections concerned with setting up a metric classroom laboratory, instructional aids and ideas, sample classroom activities, supplies and equipment, and an annotated bibliography. (MN)