The Minnesota School Mathematics and Science Teaching (MINNEMAST) Project is characterized by its emphasis on the coordination of mathematics and science in the elementary school curriculum. Units are planned to provide children with activities in which they learn various concepts from both subject areas. Each subject is used to support and reinforce the other where appropriate, with common techniques and concepts being sought and exploited. Content is presented in story fashion. The stories serve to introduce concepts and lead to activities. Imbedded in the pictures that accompany the stories are examples of the concepts presented. Several of the activities outlines in this unit on measurement closely resemble some of the experiments conducted by Piaget in his original research. The concepts presented include the principle that liquid volume is unchanged by the size or shape of its container and that a solid mass has the same displacement, regardless of its shape or form. The treatment of measurement is approached in comparative rather than absolute terms. The questions of "how much" and "how many" have been deferred until later and the usage of the terms "more than" and "less than" are presented. Worksheets and commentaries to the teacher are provided and additional activities are suggested. (JP)