The CAS Registry Mumber 106608-82-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,6,6,0 and 8 respectively; the second part has 2 digits, 8 and 2 respectively. Calculate Digit Verification of CAS Registry Number 106608-82: (8*1)+(7*0)+(6*6)+(5*6)+(4*0)+(3*8)+(2*8)+(1*2)=116 116 % 10 = 6 So 106608-82-6 is a valid CAS Registry Number.