Variation in students’ learning makes the teacher creative in delivering lessons. To cope with the 21st-century learners with diﬀerent learning styles that learn best through experience, the researcher made an innovation, “Manipulative and Interactive Strategic Intervention Material (MI-SIM).” MI-SIM is a combination of manipulative and interactive instructional tool that aims to improve the Least Mastered Skills in Science. Cluster random sampling was used for the selection of respondents at Manila Science High School. A pretest was conducted before the treatment to the experimental group. Posttest was then initialized after the treatment. Mean Test and Standard Deviation were used to evaluate the MI-SIM’s eﬀectiveness. Results showed that it had exceeded standards in sub-tasking and congruence; consequently, it had met the standards in functionality and technicality. The overall evaluation of MI-SIM revealed that it had exceeded standards and was highly acceptable. Analysis of Covariance was used to test the diﬀerence in mean posttest scores of students who experienced conventional and MI-SIM teaching methods. Results indicated that the conventional group’s mean posttest score was 36.80 (±5.00), while MI-SIM’s group was 31.57 (±4.86). The null hypothesis for the covariate pretest score was rejected while the intervention/method of teaching was not. The researcher recommends further study and evaluation of MI-SIM utilization.