The study investigated the effect of Kumon and framing teaching strategies on the retention of secondary school students in mathematics in the Delta-South Education Zone, Delta State, Nigeria. The study utilised a non-randomized pretest-posttest control group quasi-experimental design. The study population consisted of 19,201 SS2 students in the zone. The research employed a sample of 286 SS2 students, randomly selected from six intact classes. The instruments utilised were MAT and DARTM, both sanctioned by four experts. The MAT's reliability was assessed using the Kuder-Richardson Formula 20, yielding a coefficient of 0.86, whilst the DARTM's reliability was examined by the split-half approach, generating a reliability estimate of 0.81. The intervention involved teaching mathematics to the experimental groups using Kumon and structured teaching strategies, whereas the control group was instructed through an expository teaching strategy. A pretest was delivered before the treatment, followed by a post-test after the treatment, and a delayed post-test conducted three weeks later. The scores were aggregated and evaluated using mean, and ANCOVA at a 0.05 alpha level. The findings indicated a notable disparity in the average retention scores of students instructed in mathematics via the Kumon teaching strategy and the framing teaching strategy, compared to those taught through the expository teaching strategy, with a preference for the Kumon method, succeeded by the framing strategy. Moreover, there was no significant difference between the average retention scores of male and female students taught mathematics using the Kumon teaching, framing, and expository teaching strategy, among other findings. The research determined that Kumon and framing teaching strategies were helpful in improving mathematics retention among students in the Delta-South Education Zone. The findings recommend that secondary school mathematics teachers adopt and integrate the Kumon teaching strategy into their instruction, and utilise the framing teaching strategy as an alternative when the Kumon strategy is impractical.