The CAS Registry Mumber 55326-60-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,5,3,2 and 6 respectively; the second part has 2 digits, 6 and 0 respectively. Calculate Digit Verification of CAS Registry Number 55326-60: (7*5)+(6*5)+(5*3)+(4*2)+(3*6)+(2*6)+(1*0)=118 118 % 10 = 8 So 55326-60-8 is a valid CAS Registry Number.