The CAS Registry Mumber 93235-99-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,3,2,3 and 5 respectively; the second part has 2 digits, 9 and 9 respectively. Calculate Digit Verification of CAS Registry Number 93235-99: (7*9)+(6*3)+(5*2)+(4*3)+(3*5)+(2*9)+(1*9)=145 145 % 10 = 5 So 93235-99-5 is a valid CAS Registry Number.