Effect of Mental Mathematics Instructions on Primary Pupils” Mathematics Achievement and Retention in South -Eastern Nigeria.

1 Gyna-sam Nbisike2 Christy Nwagu3 Ngozi Ndubuisi-Evans4Catherine, Okpara 12 Alvan Ikoku Federal University of Education, Owerri, Imo State, Nigeria.3Imo State University, Owerri, Imo State, Nigeria Abstract The study investigated the