The CAS Registry Mumber 111189-93-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,1,1,8 and 9 respectively; the second part has 2 digits, 9 and 3 respectively. Calculate Digit Verification of CAS Registry Number 111189-93: (8*1)+(7*1)+(6*1)+(5*1)+(4*8)+(3*9)+(2*9)+(1*3)=106 106 % 10 = 6 So 111189-93-6 is a valid CAS Registry Number.