The CAS Registry Mumber 191468-74-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,9,1,4,6 and 8 respectively; the second part has 2 digits, 7 and 4 respectively. Calculate Digit Verification of CAS Registry Number 191468-74: (8*1)+(7*9)+(6*1)+(5*4)+(4*6)+(3*8)+(2*7)+(1*4)=163 163 % 10 = 3 So 191468-74-3 is a valid CAS Registry Number.