The CAS Registry Mumber 118792-33-9 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,8,7,9 and 2 respectively; the second part has 2 digits, 3 and 3 respectively. Calculate Digit Verification of CAS Registry Number 118792-33: (8*1)+(7*1)+(6*8)+(5*7)+(4*9)+(3*2)+(2*3)+(1*3)=149 149 % 10 = 9 So 118792-33-9 is a valid CAS Registry Number.