The CAS Registry Mumber 4414-63-5 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 4,4,1 and 4 respectively; the second part has 2 digits, 6 and 3 respectively. Calculate Digit Verification of CAS Registry Number 4414-63: (6*4)+(5*4)+(4*1)+(3*4)+(2*6)+(1*3)=75 75 % 10 = 5 So 4414-63-5 is a valid CAS Registry Number.