The study examined the roles of provision and effective usage of instructional materials in teaching and learning of mathematics in primary schools in the Senatorial Zone C of Niger state of Nigeria. Instructional materials (teaching aids) serve as an important channel in delivering instruction between the teachers and learners. It is a tool that connects teachers, instruction (subject content) and the learners. The population of the study was the teachers and the students in primary schools in the senatorial zone C of Niger state. The sample of this research consisted of one hundred and thirty (130) students and one hundred and thirty –four (134) teachers as respondents for the designed questionnaires. Also, thirty- nine (35) students were used for both experimental and control groups. The data collection for this research study was through the researcher developed test titled ‘Fractional Mathematics Test’ (FMT) on fractions which consisted of a ten- item objective questions. Also, the questionnaire was administered by the researchers to both the teachers and the pupils. The findings revealed that school management and teachers provided instructional materials for effective teaching and learning of mathematics in primary schools. Also, the result shows that instructional materials enhances students’ academic performance in mathematics. Therefore, it recommended that teachers should endaviour to use instructional materials to complement their teaching. Also, the educational stakeholders should intensify effort in the provision of more instructional materials to primary schools in the state