Designed to supplement the mathematics-science curriculum, this booklet contains activities which provide students of grades three and four with opportunities for investigating the weather and natural environment. Fourteen mathematics skills and six science processes are listed and indexed for the five activities on weather, four activities on plants and animals, two on pollution, and the four which focus on soils and rocks. Each activity consists of 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)