The CAS Registry Mumber 1530-60-5 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,5,3 and 0 respectively; the second part has 2 digits, 6 and 0 respectively. Calculate Digit Verification of CAS Registry Number 1530-60: (6*1)+(5*5)+(4*3)+(3*0)+(2*6)+(1*0)=55 55 % 10 = 5 So 1530-60-5 is a valid CAS Registry Number.