The CAS Registry Mumber 60880-63-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 6,0,8,8 and 0 respectively; the second part has 2 digits, 6 and 3 respectively. Calculate Digit Verification of CAS Registry Number 60880-63: (7*6)+(6*0)+(5*8)+(4*8)+(3*0)+(2*6)+(1*3)=129 129 % 10 = 9 So 60880-63-9 is a valid CAS Registry Number.