The CAS Registry Mumber 84404-94-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,4,4,0 and 4 respectively; the second part has 2 digits, 9 and 4 respectively. Calculate Digit Verification of CAS Registry Number 84404-94: (7*8)+(6*4)+(5*4)+(4*0)+(3*4)+(2*9)+(1*4)=134 134 % 10 = 4 So 84404-94-4 is a valid CAS Registry Number.