The objective of this book is to identify those mathematical concepts which are relevant to elementary measurement, and to exhibit their logical interrelationships. The book was written with high school mathematics teachers in mind, but it is hoped that it will be useful also to elementary school teachers, science teachers, and college teachers. The book could be useful as a text for an advanced undergraduate course, or as an inservice course for teachers. The mathematical background required is approximately that which is included in a good high school education. Sections in the book include: (1) Measurement and Measure Functions; (2) The Measurement of Numerosity and Length; (3) The Measurement of Angles, Area, and Volume; and (4) Measurement and Dimension. A list of references conclude the publication. Each section includes background information, discussion of concepts, some suggestions for instruction, and exercises. (RH)