The CAS Registry Mumber 99314-93-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,9,3,1 and 4 respectively; the second part has 2 digits, 9 and 3 respectively. Calculate Digit Verification of CAS Registry Number 99314-93: (7*9)+(6*9)+(5*3)+(4*1)+(3*4)+(2*9)+(1*3)=169 169 % 10 = 9 So 99314-93-9 is a valid CAS Registry Number.