The CAS Registry Mumber 162226-16-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,6,2,2,2 and 6 respectively; the second part has 2 digits, 1 and 6 respectively. Calculate Digit Verification of CAS Registry Number 162226-16: (8*1)+(7*6)+(6*2)+(5*2)+(4*2)+(3*6)+(2*1)+(1*6)=106 106 % 10 = 6 So 162226-16-6 is a valid CAS Registry Number.