The CAS Registry Mumber 14145-73-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,4,1,4 and 5 respectively; the second part has 2 digits, 7 and 3 respectively. Calculate Digit Verification of CAS Registry Number 14145-73: (7*1)+(6*4)+(5*1)+(4*4)+(3*5)+(2*7)+(1*3)=84 84 % 10 = 4 So 14145-73-4 is a valid CAS Registry Number.