prerecorded videocassettes in the field of mathematics

providing access to an interactive computer database [ and computer bulletin board ] in the field of mathematics

computer software in the field of mathematics

printed instructional materials in the field of mathematics and printed teachers manuals in the field of mathematics

educational services, namely conducting [ classes, seminars, workshops, ] information exchanges and conferences in the field of mathematics via interactive and electronic means; and distribution of printed materials associated therewith

single rod abacus