The CAS Registry Mumber 128922-01-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,8,9,2 and 2 respectively; the second part has 2 digits, 0 and 1 respectively. Calculate Digit Verification of CAS Registry Number 128922-01: (8*1)+(7*2)+(6*8)+(5*9)+(4*2)+(3*2)+(2*0)+(1*1)=130 130 % 10 = 0 So 128922-01-0 is a valid CAS Registry Number.