The CAS Registry Mumber 935263-65-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 9,3,5,2,6 and 3 respectively; the second part has 2 digits, 6 and 5 respectively. Calculate Digit Verification of CAS Registry Number 935263-65: (8*9)+(7*3)+(6*5)+(5*2)+(4*6)+(3*3)+(2*6)+(1*5)=183 183 % 10 = 3 So 935263-65-3 is a valid CAS Registry Number.