The CAS Registry Mumber 70449-64-8 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, 6 and 4 respectively. Calculate Digit Verification of CAS Registry Number 70449-64: (7*7)+(6*0)+(5*4)+(4*4)+(3*9)+(2*6)+(1*4)=128 128 % 10 = 8 So 70449-64-8 is a valid CAS Registry Number.