The CAS Registry Mumber 93597-99-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,3,5,9 and 7 respectively; the second part has 2 digits, 9 and 9 respectively. Calculate Digit Verification of CAS Registry Number 93597-99: (7*9)+(6*3)+(5*5)+(4*9)+(3*7)+(2*9)+(1*9)=190 190 % 10 = 0 So 93597-99-0 is a valid CAS Registry Number.