The CAS Registry Mumber 54994-44-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,4,9,9 and 4 respectively; the second part has 2 digits, 4 and 4 respectively. Calculate Digit Verification of CAS Registry Number 54994-44: (7*5)+(6*4)+(5*9)+(4*9)+(3*4)+(2*4)+(1*4)=164 164 % 10 = 4 So 54994-44-4 is a valid CAS Registry Number.