The CAS Registry Mumber 133476-13-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,3,4,7 and 6 respectively; the second part has 2 digits, 1 and 3 respectively. Calculate Digit Verification of CAS Registry Number 133476-13: (8*1)+(7*3)+(6*3)+(5*4)+(4*7)+(3*6)+(2*1)+(1*3)=118 118 % 10 = 8 So 133476-13-8 is a valid CAS Registry Number.