The CAS Registry Mumber 69604-84-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 6,9,6,0 and 4 respectively; the second part has 2 digits, 8 and 4 respectively. Calculate Digit Verification of CAS Registry Number 69604-84: (7*6)+(6*9)+(5*6)+(4*0)+(3*4)+(2*8)+(1*4)=158 158 % 10 = 8 So 69604-84-8 is a valid CAS Registry Number.