The CAS Registry Mumber 94944-66-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,4,9,4 and 4 respectively; the second part has 2 digits, 6 and 6 respectively. Calculate Digit Verification of CAS Registry Number 94944-66: (7*9)+(6*4)+(5*9)+(4*4)+(3*4)+(2*6)+(1*6)=178 178 % 10 = 8 So 94944-66-8 is a valid CAS Registry Number.