The CAS Registry Mumber 86005-09-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,6,0,0 and 5 respectively; the second part has 2 digits, 0 and 9 respectively. Calculate Digit Verification of CAS Registry Number 86005-09: (7*8)+(6*6)+(5*0)+(4*0)+(3*5)+(2*0)+(1*9)=116 116 % 10 = 6 So 86005-09-6 is a valid CAS Registry Number.