Low levels of mathematics and reading skills are associated with a range of negative outcomes in life, including reduced employment and earnings, and poor health. This review examines the impact of a broad range of school-based interventions that specifically target students with or at risk of academic difficulties in Grades K-6. The students in this review either have academic difficulties or are at risk of such difficulties because of their background. The review analyses evidence from 205 studies, 186 of which are randomised controlled trials. Peer-assisted instruction and small-group instruction by adults showed the largest (short-term) improvements in reading and mathematics. [This summary is based on Dietrichson, J., Filges, T., Seerup, J. K., Klokker, R. H., Viinholt, B. C. A., Bøg, M., & Eiberg, M. Targeted school-based interventions for improving reading and mathematics for students with or at risk of academic difficulties in Grades K-6: A systematic review. "Campbell Systematic Reviews." 2021;e1152. https://doi.org/10.1002/cl2.1152.]