In this work, we explored the relationship of the Common Core State Standards in Mathematics (CCSSM) to student achievement. Building on techniques developed for the Third International Mathematics and Science Study (TIMSS), we found a very high degree of similarity between CCSSM and the standards of the highest-achieving nations on the 1995 TIMSS. A similar analysis revealed wide variation in the proximity of state standards in effect in 2009 to the CCSSM. Finally, we used regression and analysis of covariance techniques to assess the relationship between the proximity of a state's standards to the CCSSM and performance on the 2009 National Assessment of Educational Progress (NAEP). After adjusting for cut-points on state assessments and controlling for state demographics related to socioeconomic status and poverty, we found that states with standards more like the CCSSM, on average, had higher NAEP scores. (Contains 1 note, 4 tables and 5 figures.)