The CAS Registry Mumber 28444-00-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,8,4,4 and 4 respectively; the second part has 2 digits, 0 and 0 respectively. Calculate Digit Verification of CAS Registry Number 28444-00: (7*2)+(6*8)+(5*4)+(4*4)+(3*4)+(2*0)+(1*0)=110 110 % 10 = 0 So 28444-00-0 is a valid CAS Registry Number.