The CAS Registry Mumber 4079-94-1 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 4,0,7 and 9 respectively; the second part has 2 digits, 9 and 4 respectively. Calculate Digit Verification of CAS Registry Number 4079-94: (6*4)+(5*0)+(4*7)+(3*9)+(2*9)+(1*4)=101 101 % 10 = 1 So 4079-94-1 is a valid CAS Registry Number.