This report: (1) describes the mathematics test given to Year 8 students in the Mt. Druitt Longitudinal Study in 1986; (2) describes and discusses the results; (3) analyzes errors made by the students; and (4) suggests some possible interventions to address the errors made by students. The study dates from 1975 when funds were obtained to provide intervention programs at five preschools in Mt. Druitt (Australia), an area which had been identified as being disadvantaged. These intervention programs were aimed at bridging the educational achievement gap between these "disadvantaged" students and those who were not "disadvantaged." The intervention programs ceased in 1979 when the children had completed first grade. Since that time the study has been involved in assessing educational skills, pupil attitudes, and teacher and pupil classroom behavior through testing, questionnaires, and observation. Teacher and parent interviews have also been conducted. To determine whether the early intervention assisted the Mt. Druitt students and how that "disadvantage" operated, comparison schools were chosen to undergo the same testing as the Mt. Druitt schools. In 1986, the students who were first identified in preschool in 1977 were in year eight in high school. Scripts of the 1986 test, which was administered in two parts on two separate occasions during a school week in March, are appended. (PK)