The CAS Registry Mumber 393-14-6 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 3,9 and 3 respectively; the second part has 2 digits, 1 and 4 respectively. Calculate Digit Verification of CAS Registry Number 393-14: (5*3)+(4*9)+(3*3)+(2*1)+(1*4)=66 66 % 10 = 6 So 393-14-6 is a valid CAS Registry Number.