The CAS Registry Mumber 8016-14-6 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 8,0,1 and 6 respectively; the second part has 2 digits, 1 and 4 respectively. Calculate Digit Verification of CAS Registry Number 8016-14: (6*8)+(5*0)+(4*1)+(3*6)+(2*1)+(1*4)=76 76 % 10 = 6 So 8016-14-6 is a valid CAS Registry Number.