The CAS Registry Mumber 96223-35-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,6,2,2 and 3 respectively; the second part has 2 digits, 3 and 5 respectively. Calculate Digit Verification of CAS Registry Number 96223-35: (7*9)+(6*6)+(5*2)+(4*2)+(3*3)+(2*3)+(1*5)=137 137 % 10 = 7 So 96223-35-7 is a valid CAS Registry Number.