The CAS Registry Mumber 96105-50-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,6,1,0 and 5 respectively; the second part has 2 digits, 5 and 0 respectively. Calculate Digit Verification of CAS Registry Number 96105-50: (7*9)+(6*6)+(5*1)+(4*0)+(3*5)+(2*5)+(1*0)=129 129 % 10 = 9 So 96105-50-9 is a valid CAS Registry Number.