The CAS Registry Mumber 4362-02-1 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 4,3,6 and 2 respectively; the second part has 2 digits, 0 and 2 respectively. Calculate Digit Verification of CAS Registry Number 4362-02: (6*4)+(5*3)+(4*6)+(3*2)+(2*0)+(1*2)=71 71 % 10 = 1 So 4362-02-1 is a valid CAS Registry Number.