The CAS Registry Mumber 130392-75-5 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,0,3,9 and 2 respectively; the second part has 2 digits, 7 and 5 respectively. Calculate Digit Verification of CAS Registry Number 130392-75: (8*1)+(7*3)+(6*0)+(5*3)+(4*9)+(3*2)+(2*7)+(1*5)=105 105 % 10 = 5 So 130392-75-5 is a valid CAS Registry Number.