The CAS Registry Mumber 2007-94-5 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 2,0,0 and 7 respectively; the second part has 2 digits, 9 and 4 respectively. Calculate Digit Verification of CAS Registry Number 2007-94: (6*2)+(5*0)+(4*0)+(3*7)+(2*9)+(1*4)=55 55 % 10 = 5 So 2007-94-5 is a valid CAS Registry Number.