This fourth module in a sequence of instructional modules for preservice elementary teachers deals with the laboratory approach to mathematics. The module focuses on laboratory activities aimed at readiness, concept development, concept synthesis, recall, application, planning, evaluation, and remediation. Objectives for the module, prerequisites, pre- and post-assessment standards, and remediation activities are listed along with 9 instructional activities for the preservice teachers to complete. Eleven reading handouts covering laboratory organization, instructional approaches, and instructional materials are included. (DT)