The CAS Registry Mumber 81067-09-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,1,0,6 and 7 respectively; the second part has 2 digits, 0 and 9 respectively. Calculate Digit Verification of CAS Registry Number 81067-09: (7*8)+(6*1)+(5*0)+(4*6)+(3*7)+(2*0)+(1*9)=116 116 % 10 = 6 So 81067-09-6 is a valid CAS Registry Number.