Developed to serve as a way to integrate mathematics skills and science processes, this booklet provides activities which demonstrate the concept of density for students of grades five through nine. Investigations are offered on the densities of water, salt, salt water, and woods. Opportunities are also provided in computing volumes of cylinders and spheres. Each of the 26 activities have both student sheets and a teacher's guide. The teacher's guide contains information on the activities including: (1) topic area; (2) introductory statement; (3) math and science skills; (4) required materials; (5) key questions; (6) background information; (7) management details; (8) instructional procedures; (9) student procedures; (10) discussion questions; (11) activity extensions; and (12) curriculum coordinates. (ML)