The CAS Registry Mumber 1197916-12-3 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,1,9,7,9,1 and 6 respectively; the second part has 2 digits, 1 and 2 respectively. Calculate Digit Verification of CAS Registry Number 1197916-12: (9*1)+(8*1)+(7*9)+(6*7)+(5*9)+(4*1)+(3*6)+(2*1)+(1*2)=193 193 % 10 = 3 So 1197916-12-3 is a valid CAS Registry Number.