The CAS Registry Mumber 94104-38-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,4,1,0 and 4 respectively; the second part has 2 digits, 3 and 8 respectively. Calculate Digit Verification of CAS Registry Number 94104-38: (7*9)+(6*4)+(5*1)+(4*0)+(3*4)+(2*3)+(1*8)=118 118 % 10 = 8 So 94104-38-8 is a valid CAS Registry Number.