The CAS Registry Mumber 32869-75-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,2,8,6 and 9 respectively; the second part has 2 digits, 7 and 5 respectively. Calculate Digit Verification of CAS Registry Number 32869-75: (7*3)+(6*2)+(5*8)+(4*6)+(3*9)+(2*7)+(1*5)=143 143 % 10 = 3 So 32869-75-3 is a valid CAS Registry Number.