The CAS Registry Mumber 82459-66-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,2,4,5 and 9 respectively; the second part has 2 digits, 6 and 6 respectively. Calculate Digit Verification of CAS Registry Number 82459-66: (7*8)+(6*2)+(5*4)+(4*5)+(3*9)+(2*6)+(1*6)=153 153 % 10 = 3 So 82459-66-3 is a valid CAS Registry Number.