The CAS Registry Mumber 1499-84-9 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,4,9 and 9 respectively; the second part has 2 digits, 8 and 4 respectively. Calculate Digit Verification of CAS Registry Number 1499-84: (6*1)+(5*4)+(4*9)+(3*9)+(2*8)+(1*4)=109 109 % 10 = 9 So 1499-84-9 is a valid CAS Registry Number.