New Classrooms Innovation Partners was awarded an Investing in Innovation (i3) grant from the U.S. Department of Education to implement its "Teach to One: Math" (TtO) model in five schools in Elizabeth, New Jersey, for three academic years, beginning in September 2015 and continuing through June 2018. The Consortium for Policy Research in Education (CPRE) at Teachers College, Columbia University, recently concluded a four-year evaluation of these efforts. The evaluation had two primary strands: (1) a methodologically rigorous quantitative study of TtO's impact on student mathematics performance; and (2) a systematic qualitative analysis of TtO's implementation processes, combined with yearly New Classrooms and school staff interviews, student focus groups, and classroom observations in each of the five TtO schools. This report describes the results of the first strand, focusing exclusively on the quantitative impact results. Performance patterns across the five TtO treatment schools were quite inconsistent, and the TtO estimates for each of the three implementation years were statistically non-significant.