This manual was designed for use in conducting staff development sessions for elementary teachers of mathematics in Mississippi in grades K-6. The four topical areas treated in the document are: (1) measurement and geometry; (2) fractions; (3) procedural errors in arithmetic; and (4) problem solving. The number of instructional hours necessary for completing the activities for each topic varies from 2 to 12 hours. The entire instructional program may require from 40-60 hours, depending upon the skill and knowledge base of the participating teachers. The manual was written as an instruction guide for a staff development leader. Each topic begins with a brief overview followed by a series of instructional activities. For each activity, information for the leaders is listed in summary form, followed by the instructional materials to be used, and a description of advanced preparation. Various types of teaching aids, worksheets, record sheets, activity cards, and transparency masters are incorporated into the guide. Since most of the instructional activities require the hands-on manipulation of materials, a maximum of 30 teachers per workshop is recommended. (TW)