•This study conducted a two-year-long experiment on a structured pedagogy program.•The program targeted mathematics for lower secondary education in El Salvador.•The one-year impact on math learning is estimated at 0.17 standard deviations.•The impact remained positive but became not statistically significant in year 2.•The interventions had positive impacts on math teaching and student study at home. The learning crisis in lower secondary education is profound. Evidence suggests that a structured pedagogy program that combines the distribution of teaching and learning materials with different interventions is an effective approach. Given a variety of possible combinations of interventions in a program, this study conducted a two-year-long experiment on additional interventions in a program for mathematics in El Salvador. The distribution of mathematics tests and workbooks were included to a program to strengthen support of teachers for students. The average one-year impact on mathematics learning is estimated at 0.17 standard deviations. The impact remained positive but became not statistically significant in the second year of research when the difference of interventions between the treatment and control groups disappeared.