The CAS Registry Mumber 65273-35-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 6,5,2,7 and 3 respectively; the second part has 2 digits, 3 and 5 respectively. Calculate Digit Verification of CAS Registry Number 65273-35: (7*6)+(6*5)+(5*2)+(4*7)+(3*3)+(2*3)+(1*5)=130 130 % 10 = 0 So 65273-35-0 is a valid CAS Registry Number.