The CAS Registry Mumber 1186668-69-8 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,1,8,6,6,6 and 8 respectively; the second part has 2 digits, 6 and 9 respectively. Calculate Digit Verification of CAS Registry Number 1186668-69: (9*1)+(8*1)+(7*8)+(6*6)+(5*6)+(4*6)+(3*8)+(2*6)+(1*9)=208 208 % 10 = 8 So 1186668-69-8 is a valid CAS Registry Number.