The CAS Registry Mumber 119123-51-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,9,1,2 and 3 respectively; the second part has 2 digits, 5 and 1 respectively. Calculate Digit Verification of CAS Registry Number 119123-51: (8*1)+(7*1)+(6*9)+(5*1)+(4*2)+(3*3)+(2*5)+(1*1)=102 102 % 10 = 2 So 119123-51-2 is a valid CAS Registry Number.