The CAS Registry Mumber 95716-66-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,5,7,1 and 6 respectively; the second part has 2 digits, 6 and 6 respectively. Calculate Digit Verification of CAS Registry Number 95716-66: (7*9)+(6*5)+(5*7)+(4*1)+(3*6)+(2*6)+(1*6)=168 168 % 10 = 8 So 95716-66-8 is a valid CAS Registry Number.