Approximately, 283 sixth-grade students completed four randomly generated Math Curriculum-Based Measures (M-CBMs) from interventioncentral.org twice during a fall semester. These M-CBMs measured foundational skills in addition, subtraction, multiplication, and division. We found that using mean fluency or accuracy scores from four M-CBMs produced more reliable test-retest estimates (e.g., r = 0.86-0.88) in comparison with using individual scores (e.g., r = 0.55-0.73). We also found that aggregated (mean or median) and individual M-CBM scores were strongly correlated (e.g., r = 0.82-0.85) with the Palmetto Achievement Challenge Test (PACT) math section, an annual state standardized test. However, only aggregated M-CBMs produced efficient cut scores useful in detecting students who would pass or fail the PACT.