This booklet is written for the non-technical person and is oriented around the needs of everyday life. The relative size of metric units of measure is illustrated through common and familiar objects. This informal approach provides an introduction to units of distance measure, volume, weight, and temperature in the metric system. Part II of this booklet relates some of the historical background of the metric system and presents the latest international recommendations that are not yet in use in many metric countries. Advantages and claimed disadvantages for or against the adoption of the metric system are reviewed and suggested teaching practices for those who want to help others learn the system are presented. (JP)