The CAS Registry Mumber 4486-43-5 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 4,4,8 and 6 respectively; the second part has 2 digits, 4 and 3 respectively. Calculate Digit Verification of CAS Registry Number 4486-43: (6*4)+(5*4)+(4*8)+(3*6)+(2*4)+(1*3)=105 105 % 10 = 5 So 4486-43-5 is a valid CAS Registry Number.