The CAS Registry Mumber 4016-94-8 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 4,0,1 and 6 respectively; the second part has 2 digits, 9 and 4 respectively. Calculate Digit Verification of CAS Registry Number 4016-94: (6*4)+(5*0)+(4*1)+(3*6)+(2*9)+(1*4)=68 68 % 10 = 8 So 4016-94-8 is a valid CAS Registry Number.