The CAS Registry Mumber 84029-04-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,4,0,2 and 9 respectively; the second part has 2 digits, 0 and 4 respectively. Calculate Digit Verification of CAS Registry Number 84029-04: (7*8)+(6*4)+(5*0)+(4*2)+(3*9)+(2*0)+(1*4)=119 119 % 10 = 9 So 84029-04-9 is a valid CAS Registry Number.