The purpose of this study was to determine if students who scored in the lower percentiles range (1st to 10th) on the spring 2017 NWEA MAP assessment obtained a post ADDITION 1 score in BlueStreak Math during the 2017-18 school year had higher observed growth in RIT scores than students who scored in the lower percentiles ranges but did not obtain a post ADDITION 1 score. This analysis of BlueStreak Math's impact on mathematics achievement of elementary school students meets the Elementary and Secondary Education Act (ESSA) Tier II standard for being an evidence-based intervention. In accordance with this standard, this study used a pretest-posttest quasi-experimental design that had no selection bias on the part of BlueStreak Math or as part of this evaluation. Our treatment control groups were well-matched for analysis following ESSA and What Works Clearinghouse (WWC) guidelines. As required by ESSA Tier II standards, this study measured outcomes using a reliable benchmark assessment (NWEA MAP). The demographics of students, in grades 3rd-5th, sampled for this study was highly homogenous (99 percent ethnic minority and more than 90 percent economically disadvantaged). Students in Grade 3 that completed a post-test in at least ADDITITON 1 during the 2017-18 school year had a mean RIT score growth of 14.3 points, which was 8.5 points greater than students in grade 3 that did not take a post-test in BlueStreak Math ADDITION 1. Students that completed a post-test in at least ADDITION 1 during the 2017-18 school year had a mean RIT score growth of 11.9 points, which was 9.2 points greater than students in grades 3--5 combined that did not take a post-test in BlueStreak Math ADDITION 1. Educators seeking an intervention solution to enhance students' math performance may explore the BlueStreak method as a means to boost academic achievement. The following is appended: (1) Data in Support of BlueStreak Math's Impact on Growth of RIT Scores for Lower-performing Students in Grades 3-5 Study.