The CAS Registry Mumber 85908-82-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,5,9,0 and 8 respectively; the second part has 2 digits, 8 and 2 respectively. Calculate Digit Verification of CAS Registry Number 85908-82: (7*8)+(6*5)+(5*9)+(4*0)+(3*8)+(2*8)+(1*2)=173 173 % 10 = 3 So 85908-82-3 is a valid CAS Registry Number.