The CAS Registry Mumber 185432-27-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,8,5,4,3 and 2 respectively; the second part has 2 digits, 2 and 7 respectively. Calculate Digit Verification of CAS Registry Number 185432-27: (8*1)+(7*8)+(6*5)+(5*4)+(4*3)+(3*2)+(2*2)+(1*7)=143 143 % 10 = 3 So 185432-27-3 is a valid CAS Registry Number.