The CAS Registry Mumber 130029-28-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,0,0,2 and 9 respectively; the second part has 2 digits, 2 and 8 respectively. Calculate Digit Verification of CAS Registry Number 130029-28: (8*1)+(7*3)+(6*0)+(5*0)+(4*2)+(3*9)+(2*2)+(1*8)=76 76 % 10 = 6 So 130029-28-6 is a valid CAS Registry Number.