The CAS Registry Mumber 145111-67-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,5,1,1 and 1 respectively; the second part has 2 digits, 6 and 7 respectively. Calculate Digit Verification of CAS Registry Number 145111-67: (8*1)+(7*4)+(6*5)+(5*1)+(4*1)+(3*1)+(2*6)+(1*7)=97 97 % 10 = 7 So 145111-67-7 is a valid CAS Registry Number.