The CAS Registry Mumber 130179-76-9 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,0,1,7 and 9 respectively; the second part has 2 digits, 7 and 6 respectively. Calculate Digit Verification of CAS Registry Number 130179-76: (8*1)+(7*3)+(6*0)+(5*1)+(4*7)+(3*9)+(2*7)+(1*6)=109 109 % 10 = 9 So 130179-76-9 is a valid CAS Registry Number.