The CAS Registry Mumber 11140-05-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,1,1,4 and 0 respectively; the second part has 2 digits, 0 and 5 respectively. Calculate Digit Verification of CAS Registry Number 11140-05: (7*1)+(6*1)+(5*1)+(4*4)+(3*0)+(2*0)+(1*5)=39 39 % 10 = 9 So 11140-05-9 is a valid CAS Registry Number.