The CAS Registry Mumber 123073-60-9 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,3,0,7 and 3 respectively; the second part has 2 digits, 6 and 0 respectively. Calculate Digit Verification of CAS Registry Number 123073-60: (8*1)+(7*2)+(6*3)+(5*0)+(4*7)+(3*3)+(2*6)+(1*0)=89 89 % 10 = 9 So 123073-60-9 is a valid CAS Registry Number.