The current study was framed to determine the gap between intended and enacted single national mathematics curriculum implementation determinants instructional material, teaching methods, formative assessment, and teachers’ professional development. The nature of the study was quantitative descriptive based on the survey method. Single National Curriculum of Mathematics Implementation Questionnaire for Teachers (SNCMIQT) was developed for data collection from public primary school mathematics teachers. Content validity of SNCMIQT was ensured by five curriculum education experts and reliability was calculated employing Cronbach’s Alpha score; .918, and used to collect the data from the sample of 230 teachers selected through a simple random sampling technique. The collected data were analyzed by applying descriptive and inferential statistics. The study results revealed that 82% of mathematics curriculum determinants were implemented and an 18% gap existed regarding SNC mathematics. The results further, showed that 78% of instructional materials were in use and a 22% gap existed regarding instructional materials. The results declared that 78% of teaching methods were used according to the SNC and a 22% gap existed in teaching methods. The results declared that 87% of formative assessment techniques were in use, while a 13% gap existed regarding the usage of formative assessment. The results revealed that 87% of teachers were provided with teacher training, while 13% were not provided with teacher training, furthermore, results declared no significant difference between locale curriculum implementation determinants. Based on the results of the study, it was recommended that the government provide funds for mathematics instructional materials; learning labs, teaching kits, and learning gadgets for the mathematics curriculum. The education department and head teachers ensured the implementation of curriculum-based teaching methods and formative assessment strategies. Teachers training institutions may provide mathematics curriculum-based teachers training on the usage of instructional materials, teaching methods, and assessment. Head teachers may bind teachers in using instructional materials, teaching methods, and formative assessment techniques for effective SNC mathematics curriculum implementation.