Provided are the printed instructional materials for the Science Curriculum Improvement Study (SCIS) Unit Position and Motion. This unit is a continuation of the part of the teaching program centering on space-time relations. The principle new idea introduced in this unit is that of the reference frame, a systematic selection of reference objects and directions. The unit consists of four parts. In part one the concept of reference objects is reviewed and the reference frame concept is introduced. In parts two and three, the children use polar and rectangular coordiantes to make accurate descriptions of the relative positions of objects and places. Part four is experiment oriented; it deals with the motion and interaction of rolling spheres. Coordinates are used to describe the spheres trajectories in these activities, and the variables which influence the motion and affect the tracks left by rolling spheres are investigated. (RS)