Despite the vast research on the early predictors of mathematics achievement, little research has investigated the predictors of various domains of mathematics (e.g., geometry, statistics). The purpose of the present study was to examine the predictive relation between first-grade early numeracy and computation skills and third-grade mathematics achievement as measured by a state test. Furthermore, we explored the relations between these measures for students who were Below Proficient and Proficient. Findings suggest that proficiency level matters when examining the relation between mathematics skills. Also, there are different patterns of significant predictors depending on the domain of later mathematics achievement and whether or not reading achievement was considered. Findings are discussed in the context of mathematics learning for students with mathematics difficulty.