The CAS Registry Mumber 96105-52-1 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 2 respectively. Calculate Digit Verification of CAS Registry Number 96105-52: (7*9)+(6*6)+(5*1)+(4*0)+(3*5)+(2*5)+(1*2)=131 131 % 10 = 1 So 96105-52-1 is a valid CAS Registry Number.