The CAS Registry Mumber 84199-82-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,4,1,9 and 9 respectively; the second part has 2 digits, 8 and 2 respectively. Calculate Digit Verification of CAS Registry Number 84199-82: (7*8)+(6*4)+(5*1)+(4*9)+(3*9)+(2*8)+(1*2)=166 166 % 10 = 6 So 84199-82-6 is a valid CAS Registry Number.