The CAS Registry Mumber 144303-79-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,4,3,0 and 3 respectively; the second part has 2 digits, 7 and 9 respectively. Calculate Digit Verification of CAS Registry Number 144303-79: (8*1)+(7*4)+(6*4)+(5*3)+(4*0)+(3*3)+(2*7)+(1*9)=107 107 % 10 = 7 So 144303-79-7 is a valid CAS Registry Number.