The CAS Registry Mumber 146098-28-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,6,0,9 and 8 respectively; the second part has 2 digits, 2 and 8 respectively. Calculate Digit Verification of CAS Registry Number 146098-28: (8*1)+(7*4)+(6*6)+(5*0)+(4*9)+(3*8)+(2*2)+(1*8)=144 144 % 10 = 4 So 146098-28-4 is a valid CAS Registry Number.