The CAS Registry Mumber 4414-58-8 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, 5 and 8 respectively. Calculate Digit Verification of CAS Registry Number 4414-58: (6*4)+(5*4)+(4*1)+(3*4)+(2*5)+(1*8)=78 78 % 10 = 8 So 4414-58-8 is a valid CAS Registry Number.