Amoah, D. (trans.) (2019) “Using an Improvised Abacus to Assist Samproso M/A Junior High School Level One Pupils to Overcome the Problem of Place Value Concept in Mathematics”, International Journal of Scientific Research and Management (IJSRM), 7(06), pp. 144–165. doi:10.18535/ijsrm/v7i6.m01.