The CAS Registry Mumber 132928-93-9 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,2,9,2 and 8 respectively; the second part has 2 digits, 9 and 3 respectively. Calculate Digit Verification of CAS Registry Number 132928-93: (8*1)+(7*3)+(6*2)+(5*9)+(4*2)+(3*8)+(2*9)+(1*3)=139 139 % 10 = 9 So 132928-93-9 is a valid CAS Registry Number.