The CAS Registry Mumber 5035-30-3 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 5,0,3 and 5 respectively; the second part has 2 digits, 3 and 0 respectively. Calculate Digit Verification of CAS Registry Number 5035-30: (6*5)+(5*0)+(4*3)+(3*5)+(2*3)+(1*0)=63 63 % 10 = 3 So 5035-30-3 is a valid CAS Registry Number.