The CAS Registry Mumber 35129-44-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,5,1,2 and 9 respectively; the second part has 2 digits, 4 and 4 respectively. Calculate Digit Verification of CAS Registry Number 35129-44: (7*3)+(6*5)+(5*1)+(4*2)+(3*9)+(2*4)+(1*4)=103 103 % 10 = 3 So 35129-44-3 is a valid CAS Registry Number.