The CAS Registry Mumber 54245-62-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,4,2,4 and 5 respectively; the second part has 2 digits, 6 and 2 respectively. Calculate Digit Verification of CAS Registry Number 54245-62: (7*5)+(6*4)+(5*2)+(4*4)+(3*5)+(2*6)+(1*2)=114 114 % 10 = 4 So 54245-62-4 is a valid CAS Registry Number.