The CAS Registry Mumber 16144-94-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,6,1,4 and 4 respectively; the second part has 2 digits, 9 and 4 respectively. Calculate Digit Verification of CAS Registry Number 16144-94: (7*1)+(6*6)+(5*1)+(4*4)+(3*4)+(2*9)+(1*4)=98 98 % 10 = 8 So 16144-94-8 is a valid CAS Registry Number.