The CAS Registry Mumber 4519-11-3 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 4,5,1 and 9 respectively; the second part has 2 digits, 1 and 1 respectively. Calculate Digit Verification of CAS Registry Number 4519-11: (6*4)+(5*5)+(4*1)+(3*9)+(2*1)+(1*1)=83 83 % 10 = 3 So 4519-11-3 is a valid CAS Registry Number.