The CAS Registry Mumber 119817-92-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,9,8,1 and 7 respectively; the second part has 2 digits, 9 and 2 respectively. Calculate Digit Verification of CAS Registry Number 119817-92: (8*1)+(7*1)+(6*9)+(5*8)+(4*1)+(3*7)+(2*9)+(1*2)=154 154 % 10 = 4 So 119817-92-4 is a valid CAS Registry Number.