This book is designed as a report and an in-service tool for teachers of grades K-6. It is built around the idea that the standard textbook treatment of metric measurement gives rise to many misconceptions among primary grade children. This report is a record of the development of alternative methods for introducing measuring activities to first-grade children. Sections of the book are organized by clusters of related problem-solving activities and strategies. The major sections are titled: Size Discrimination; Non-standard Units of Measurement; and Measuring with Standard Units. The objectives are: (1) to be able to use a unit of measure with reasonable accuracy; (2) to record results of observations in several forms; (3) to estimate with increasing accuracy; (4) to give reasons to support estimates; (5) to choose an appropriate instrument for the measuring task; and (6) to transfer learnings to the system of imperial measures. (MP)