The CAS Registry Mumber 123030-22-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,3,0,3 and 0 respectively; the second part has 2 digits, 2 and 2 respectively. Calculate Digit Verification of CAS Registry Number 123030-22: (8*1)+(7*2)+(6*3)+(5*0)+(4*3)+(3*0)+(2*2)+(1*2)=58 58 % 10 = 8 So 123030-22-8 is a valid CAS Registry Number.