The CAS Registry Mumber 829-82-3 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 8,2 and 9 respectively; the second part has 2 digits, 8 and 2 respectively. Calculate Digit Verification of CAS Registry Number 829-82: (5*8)+(4*2)+(3*9)+(2*8)+(1*2)=93 93 % 10 = 3 So 829-82-3 is a valid CAS Registry Number.