The CAS Registry Mumber 81469-85-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,1,4,6 and 9 respectively; the second part has 2 digits, 8 and 5 respectively. Calculate Digit Verification of CAS Registry Number 81469-85: (7*8)+(6*1)+(5*4)+(4*6)+(3*9)+(2*8)+(1*5)=154 154 % 10 = 4 So 81469-85-4 is a valid CAS Registry Number.