A comparative study of the effect of the methods of decomposition and base complement addition on Ghanaian children's perfomance on compound substraction: A comparative study of the effect of the methods of decomposition and base complement addition on Ghanaian children's perfomance on compound substraction

This paper compares the effects of teaching using the methods of Decomposition and the Base Complement Addition (BCA) on primary school children’s ability to solve compound subtraction problems in Ghana. Ninety-six (96) primary 2 children from two schools participated in the study. For four weeks, children in one of the participating schools were taught using the Base Complement method while their counterparts in the other school were taught using the Decomposition method. A pre-test and a post-test were organised for both groups before and after the teaching sessions respectively. In addition, four weeks after the teaching sessions a retention test was conducted. The study revealed that Base Complement Addition method of performing compound subtraction improved the performance of primary school children better than and had a higher power for retention than the Decomposition method. In addition, the differences in performance between the two groups as measured by the effect sizes (0.585 and 0.499 respectively at the post and retention-test levels), was medium and therefore non trivial. Interpretation of these effect sizes has been discussed. In addition, recommendations for teacher professional development, curriculum developers and for further studies have been made