The CAS Registry Mumber 54475-62-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,4,4,7 and 5 respectively; the second part has 2 digits, 6 and 2 respectively. Calculate Digit Verification of CAS Registry Number 54475-62: (7*5)+(6*4)+(5*4)+(4*7)+(3*5)+(2*6)+(1*2)=136 136 % 10 = 6 So 54475-62-6 is a valid CAS Registry Number.