The CAS Registry Mumber 332343-82-5 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 3,3,2,3,4 and 3 respectively; the second part has 2 digits, 8 and 2 respectively. Calculate Digit Verification of CAS Registry Number 332343-82: (8*3)+(7*3)+(6*2)+(5*3)+(4*4)+(3*3)+(2*8)+(1*2)=115 115 % 10 = 5 So 332343-82-5 is a valid CAS Registry Number.