The research shows a strong pattern of positive effects on children’s early math achievement across a range of curricula with a focus on number and operations. Eleven studies evaluated the effectiveness of instruction in only number and operations, and all 11 studies found at least one positive effect on basic number concepts or operations. The other 12 studies evaluated the effectiveness of instruction in number and operations in the context of broader curricula. None of the 23 studies that contributed to the body of evidence for Recommendation 1 evaluated the effectiveness of instruction based on a developmental progression compared to instruction that was not guided by a developmental progression. As a result, the panel could not identify evidence for teaching based on any particular developmental progression. Additional research is needed to identify the developmental progression that reflects how most children learn math. Yet based on their expertise, and the pattern of positive effects for interventions guided by a developmental progression, the panel recommends the use of a developmental progression to guide instruction in number and operations.
Positive effects were found even in studies in which the comparison group also received instruction in number and operations. The panel classified an intervention as having a focus on number and operations if it included instruction in at least one concept related to number and operations. The panel found that the math instruction received by the comparison group differed across the studies, and in some cases the panel was unable to determine what math instruction the comparison group received. Despite these limitations, the panel believes interventions with a focus on number and operations improve the math skills of young children. Although the research tended to show positive effects, some of these effects may have been driven by factors other than the instruction that was delivered in the area of number and operations. For example, most interventions included practices associated with multiple recommendations in this guide (also known as multi-component interventions). As a result, it was not possible to determine whether findings were due to a single practice— and if so, which one—or a combination of practices that could be related to multiple recommendations in this guide. While the panel cannot determine whether a single practice or combination of practices is responsible for the positive effects seen, the pattern of positive effects indicates instruction in teaching number and operations will improve children’s math skills. The panel identified five suggestions for how to carry out this recommendation.