The CAS Registry Mumber 90322-80-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,0,3,2 and 2 respectively; the second part has 2 digits, 8 and 0 respectively. Calculate Digit Verification of CAS Registry Number 90322-80: (7*9)+(6*0)+(5*3)+(4*2)+(3*2)+(2*8)+(1*0)=108 108 % 10 = 8 So 90322-80-8 is a valid CAS Registry Number.