The CAS Registry Mumber 308255-96-1 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 3,0,8,2,5 and 5 respectively; the second part has 2 digits, 9 and 6 respectively. Calculate Digit Verification of CAS Registry Number 308255-96: (8*3)+(7*0)+(6*8)+(5*2)+(4*5)+(3*5)+(2*9)+(1*6)=141 141 % 10 = 1 So 308255-96-1 is a valid CAS Registry Number.