MENTAL COMPUTATION PERFORMANCE: AN INTERVENTION STUDY WITH YEAR 5 STUDENTS

This paper presents the prepared and results of intervention using instructional materials on the development of mental computation of a sample of 51 year 5 students. It comprises 25 students for experimental group and 26 students for control group. The performance of mental computation among students was not satisfied before the intervention was enacted as it was shown in the result of pre-test. Mental computation was quite a new topic for all of students in this study, they all never found such the problem in their previous experience of learning mathematics both formally and informally. However, they found that the instructional materials were not only challenging their mind but also very interesting. After the instructional intervention, experimental students' achievement was significantly higher than that of the control group. The data showed that mental computation can be developed through appropriate intervention. The findings in this study can benefit teachers who teach mathematics at elementary school in considering materials the will teach beyond the routine procedure.