The CAS Registry Mumber 6483-85-8 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 6,4,8 and 3 respectively; the second part has 2 digits, 8 and 5 respectively. Calculate Digit Verification of CAS Registry Number 6483-85: (6*6)+(5*4)+(4*8)+(3*3)+(2*8)+(1*5)=118 118 % 10 = 8 So 6483-85-8 is a valid CAS Registry Number.