The CAS Registry Mumber 70449-44-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,0,4,4 and 9 respectively; the second part has 2 digits, 4 and 4 respectively. Calculate Digit Verification of CAS Registry Number 70449-44: (7*7)+(6*0)+(5*4)+(4*4)+(3*9)+(2*4)+(1*4)=124 124 % 10 = 4 So 70449-44-4 is a valid CAS Registry Number.