The CAS Registry Mumber 169522-11-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,6,9,5,2 and 2 respectively; the second part has 2 digits, 1 and 1 respectively. Calculate Digit Verification of CAS Registry Number 169522-11: (8*1)+(7*6)+(6*9)+(5*5)+(4*2)+(3*2)+(2*1)+(1*1)=146 146 % 10 = 6 So 169522-11-6 is a valid CAS Registry Number.