The CAS Registry Mumber 96552-86-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,6,5,5 and 2 respectively; the second part has 2 digits, 8 and 6 respectively. Calculate Digit Verification of CAS Registry Number 96552-86: (7*9)+(6*6)+(5*5)+(4*5)+(3*2)+(2*8)+(1*6)=172 172 % 10 = 2 So 96552-86-2 is a valid CAS Registry Number.