The CAS Registry Mumber 80926-09-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,0,9,2 and 6 respectively; the second part has 2 digits, 0 and 9 respectively. Calculate Digit Verification of CAS Registry Number 80926-09: (7*8)+(6*0)+(5*9)+(4*2)+(3*6)+(2*0)+(1*9)=136 136 % 10 = 6 So 80926-09-6 is a valid CAS Registry Number.