Vol. 6 No 1 2022 Journal of Contemporary Issues in Education 86 TEACHERS' PROFICIENCY IN DEVELOPING PUPILS' MENTAL ABILITIES IN DELTA STATE DAY-CARE FACILITIES, NIGERIA NKEDISHU Victor Chukwubueze Department of Educational Management and Foundations, Delta State University, Abraka Abstract This study investigated teachers' proficiency in developing pupils' mental abilities in Delta State day-care facilities, Nigeria. A quantitative survey was adopted to obtain information about the level of teachers’ proficiency and the development of pupils' mental ability. The population of the study comprises of 3,339 public school head teachers and teachers teaching in primary one and two, where pupils between the ages of three and six are found. A purposive sampling technique was adopted by the researcher to select 668 respondents, representing 20% of the entire population. The researcher utilised two self-constructed instruments titled “Teachers’ Proficiency Questionnaire (TPQ)” and “Development of Pupils' Mental Ability Questionnaire (DPMAQ)” to obtain information from respondents, which were validated through face and content validity. A Cronbach alpha reliability test was used to obtain the internal consistency of the instrument and a coefficient index of 0.75 was obtained for the Teachers’ Proficiency Questionnaire (TPQ) and 0.78 was obtained from the Development of Pupils' Mental Ability Questionnaire (DPMAQ). Data were analysed using mean scores and standard deviation to answer research questions, hypothesis was tested using Pearson r at .05 level of significance. Findings show that the level of teachers’ proficiency in the development of pupils' mental ability was high in Delta State day-care facilities, Nigeria. Also, teachers’ proficiency was significant to the development of pupils' mental ability in Delta State day-care facilities, Nigeria. It was therefore recommended, among others, that programmes on pupils' mental ability development should be provided to teachers occasionally. Keywords: Teachers Proficiency, Pupils Development, Mental Ability, Day-Care Facilities. Introduction Since the 1960s, there has been a worldwide surge in the number of children enrolling non-parental day-care facilities and education programmes before starting elementary school (Yeh & Liu, 2022). Some preschool in developed countries or care is the standard for most groups of children. Recently, a large part of early childhood is not spent at home but in some form of day-care facilities by the majority of children. The term "day- care" is synonymous with care centres, child care, or early childhood education and care, and has been used as various forms of non-parental centres for early education occurring before school. Relatively, day-care facilities include grandmothers, care centres, group or centre-based child care, and early education. Occasionally, day-care facilities have an explicit educational