The CAS Registry Mumber 470-53-1 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 4,7 and 0 respectively; the second part has 2 digits, 5 and 3 respectively. Calculate Digit Verification of CAS Registry Number 470-53: (5*4)+(4*7)+(3*0)+(2*5)+(1*3)=61 61 % 10 = 1 So 470-53-1 is a valid CAS Registry Number.