Standardized assessments show that over 39,000 students in Summer Boost gained, on average, nearly a month more learning in math and two and a half extra weeks in English language arts, according to a new study. Consistent attendance, lacking in some past summer school initiatives, contributed to student gains, researchers said. While the growth is significant, the fact that the study found improvement across so many sites makes the findings stand out even more, said Geoffrey Borman, a researcher at Arizona State University who led the study. “A key thing to keep in mind is the scale at which these impacts are being made,” he said. “We’re talking, in this case, about tens of thousands of students per year.”