The CAS Registry Mumber 1461-02-5 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,4,6 and 1 respectively; the second part has 2 digits, 0 and 2 respectively. Calculate Digit Verification of CAS Registry Number 1461-02: (6*1)+(5*4)+(4*6)+(3*1)+(2*0)+(1*2)=55 55 % 10 = 5 So 1461-02-5 is a valid CAS Registry Number.