The CAS Registry Mumber 122055-68-9 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,2,0,5 and 5 respectively; the second part has 2 digits, 6 and 8 respectively. Calculate Digit Verification of CAS Registry Number 122055-68: (8*1)+(7*2)+(6*2)+(5*0)+(4*5)+(3*5)+(2*6)+(1*8)=89 89 % 10 = 9 So 122055-68-9 is a valid CAS Registry Number.