This study aims to examine the accuracy of three Early Numeracy Curriculum-Based Measurements (EN-CBMs). The measures were designed to assess three different skills of number knowledge, including number identification (NI), missing number (MN), and quantity discrimination (QD). The measures were applied to a sample comprising 149 first-grade students from Sharqia South Governorate. The results showed that the EN-CBMs have good internal consistency as indicated by Cronbach's Alpha coefficients ranging between 0.81 and 0.97. In addition, the measures showed good alternate forms reliability as indicated by correlations coefficients ranging between 0.72 and 0.97. The validity of the measures was assessed by both content and face validity. Content validity was based on the use of specification tables. Face validity exhibited 100% approval by a panel of experts. Receiver Operating Characteristic curve (ROC) analysis was used to examine the diagnostic accuracy of the EN-CBMs, using the Learning Disabilities Diagnostic Inventory (LDDI) as the outcome measure. Sensitivity values ranged from 0.80 to 0.91, specificity ranged from 0.65 to 0.70, Positive Predictive Value (PPV) ranged from 0.47 to 0.57, Negative Predictive Value (NPV) ranged from 0.89 to 0.91, and diagnostic accuracy ranged from 0.69 to 0.74. Overall, results showed that EN-CBM can predict can screen for students at risk for failure in mathematics.