The CAS Registry Mumber 13386-34-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,3,3,8 and 6 respectively; the second part has 2 digits, 3 and 4 respectively. Calculate Digit Verification of CAS Registry Number 13386-34: (7*1)+(6*3)+(5*3)+(4*8)+(3*6)+(2*3)+(1*4)=100 100 % 10 = 0 So 13386-34-0 is a valid CAS Registry Number.