During the 2017-2018 school year, SEG Measurement conducted a study of the effectiveness of Imagine Math, an online system that provides individualized adaptive instruction and breaks down skills into component parts to help students develop math skills. The study examined the effectiveness of Imagine Math for improving the math skills of fourth, fifth and sixth grade students, in five school districts in California. Math skill growth among students using Imagine Math (treatment group) was compared to math skill growth among students who did not use Imagine Math (control group). The purpose for this research was to describe program impact for fourth, fifth and sixth grade students in California who used Imagine Math as supplemental math instruction. The study employed a quasi-experimental design with matched groups to compare the growth in math skills between those students who used Imagine Math as a supplemental part of their math instruction (treatment group) and comparable students who did not use Imagine Math as part of their math instruction (control group). The growth in mathematics skills was assessed using scores on the SBAC examination. Students' spring 2017 Math SBAC scores served as the pretest and spring 2018 Math SBAC scores served as the posttest. Treatment and control group participants were statistically matched using propensity score matching. Only students who met minimum requirements for using Imagine Math were included in the analysis. After creating matched groups of students who used Imagine Math and students who did not use Imagine Math, 464 fourth grade students, 226 fifth grade and 220 sixth grade California students were selected for the matched groups in the study. The math skills growth in the treatment group and the control group was compared statistically using analysis of covariance (ANCOVA). Specifically, we examined the difference in the Spring 2018 Math SBAC scores (dependent variable) between the treatment and control groups (independent variable) while controlling for the initial ability of the students from Spring 2017 Math SBAC Scores (covariate). Students who used Imagine Math showed greater growth in Math skills than comparable students who did not use Imagine Learning. Fourth grade students using Imagine Language & Literacy showed about 6 points more growth on the assessment, or 0.07 standard deviations (ES=0.07), than did fourth graders not using Imagine Math; however, the results failed to reach the traditional 0.05 level of significance. Fifth graders showed about 19 points more statistically significant growth on the assessment, or 0.22 standard deviations (ES=0.22), than did nonusers. Sixth grade students showed about 28 points more statistically significant growth on the assessment, or 0.29 standard deviations (ES=0.29), than did nonusers. The results indicate that Imagine Math is effective for improving math skills among fourth, fifth and sixth grade students who used the program.