This issue of "Investigations in Mathematics Education" contains: (1) 12 abstracts of research studies in mathematics education; (2) a list (by EJ number) of mathematics education research studies reported in the July-to-December 1984 issues of "Current Index to Journals in Education" (CIJE); and (3) a list (by ED number) of mathematics education research studies reported in the July-to-December 1984 issues of "Resources in Education" (RIE). The studies abstracted focus on: order and equivalence of rational numbers; relation between cognitions and performance of mathematics anxious students; effects of an instructional systems approach on the concept attainment of sixth-grade Anglo and Hispanic students; use of manipulatives and games in elementary school classrooms; mathematical attitudinal data on eighth-grade Japanese students measured by a semantic differential; performance using drawn, verbal, and telegraphic story problem formats; sex differences in quantitative scholastic aptitude test (SAT) performance; variations in state SAT performance; effectiveness of a cross-age tutoring program in mathematics for elementary school children; solving textbook word problems; the effects of combining cooperative learning and individualized instruction on student mathematics achievement, attitudes, and behaviors; and inducing cognitive growth in concrete operational college students. (JN)