A STUDY OF THE EFFICACY OF TEACHING EDUCABLE MENTALLY RETARDED ADOLESCENTS TO SOLVE SUBTRACTION PROBLEMS WITH PENCIL AND PAPER AND CALCULATORS UNDER SEVERAL TREATMENT CONDITIONS

The purpose of this research was to examine the effects of teaching educable mentally retarded adolescents to solve four column subtraction problems involving regrouping through three different methods: (1) pencil and paper; (2) calculators; and (3) calculators employing a rehearsal strategy using problems containing visual cues. Further, the relationship between the number of head swings used to compute subtraction problems with a calculator and computational time was investigated. Finally, the performance of the handicapped subjects with pencil and paper and calculators was compared to the performance of a sample of nonhandicapped subjects in each computational mode.

The handicapped participants, ages 13-6 to 15-8, were selected from a self-contained special education class within a junior high school setting. Forty-four, nonhandicapped, eighth grade students were also selected from the same school to participate in a pre-experimental, non-instructional, peer group assessment.

An ABCD, single-case, experimental design was used, with multiple probes introduced at staggered intervals. Days per phase ranged from four to ten. Two maintenance phases were scheduled, the first immediately subsequent to the last instructional phase, and the second 26 days later.

The results indicated significant differences in correct performance favoring calculators over pencil and paper for each handicapped subject; for five of the seven handicapped subjects calculators significantly reduced incorrect performance. There was no difference in correct or incorrect performance for the sample of nonhandicapped subjects across computational modes. Those nonhandicapped subjects who were least proficient with pencil and paper, however, benefited most from calculator utilization.

Rehearsal and visual cues significantly influenced correct performance for only one handicapped student. Maintenance of correct performance with calculators over time was excellent for each handicapped student. A positive relationship was found between head swings and time in calculator use. Finally, without calculators, handicapped students were markedly inferior to nonhandicapped students, however with calculators the performances were comparable.