The CAS Registry Mumber 73297-82-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,3,2,9 and 7 respectively; the second part has 2 digits, 8 and 2 respectively. Calculate Digit Verification of CAS Registry Number 73297-82: (7*7)+(6*3)+(5*2)+(4*9)+(3*7)+(2*8)+(1*2)=152 152 % 10 = 2 So 73297-82-2 is a valid CAS Registry Number.