The CAS Registry Mumber 602-49-3 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 6,0 and 2 respectively; the second part has 2 digits, 4 and 9 respectively. Calculate Digit Verification of CAS Registry Number 602-49: (5*6)+(4*0)+(3*2)+(2*4)+(1*9)=53 53 % 10 = 3 So 602-49-3 is a valid CAS Registry Number.