The CAS Registry Mumber 69285-18-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 6,9,2,8 and 5 respectively; the second part has 2 digits, 1 and 8 respectively. Calculate Digit Verification of CAS Registry Number 69285-18: (7*6)+(6*9)+(5*2)+(4*8)+(3*5)+(2*1)+(1*8)=163 163 % 10 = 3 So 69285-18-3 is a valid CAS Registry Number.