The CAS Registry Mumber 1140-01-8 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,1,4 and 0 respectively; the second part has 2 digits, 0 and 1 respectively. Calculate Digit Verification of CAS Registry Number 1140-01: (6*1)+(5*1)+(4*4)+(3*0)+(2*0)+(1*1)=28 28 % 10 = 8 So 1140-01-8 is a valid CAS Registry Number.