The CAS Registry Mumber 91614-23-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,1,6,1 and 4 respectively; the second part has 2 digits, 2 and 3 respectively. Calculate Digit Verification of CAS Registry Number 91614-23: (7*9)+(6*1)+(5*6)+(4*1)+(3*4)+(2*2)+(1*3)=122 122 % 10 = 2 So 91614-23-2 is a valid CAS Registry Number.