The CAS Registry Mumber 4500-14-5 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 4,5,0 and 0 respectively; the second part has 2 digits, 1 and 4 respectively. Calculate Digit Verification of CAS Registry Number 4500-14: (6*4)+(5*5)+(4*0)+(3*0)+(2*1)+(1*4)=55 55 % 10 = 5 So 4500-14-5 is a valid CAS Registry Number.