The CAS Registry Mumber 147984-98-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,7,9,8 and 4 respectively; the second part has 2 digits, 9 and 8 respectively. Calculate Digit Verification of CAS Registry Number 147984-98: (8*1)+(7*4)+(6*7)+(5*9)+(4*8)+(3*4)+(2*9)+(1*8)=193 193 % 10 = 3 So 147984-98-3 is a valid CAS Registry Number.