The CAS Registry Mumber 118684-14-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,8,6,8 and 4 respectively; the second part has 2 digits, 1 and 4 respectively. Calculate Digit Verification of CAS Registry Number 118684-14: (8*1)+(7*1)+(6*8)+(5*6)+(4*8)+(3*4)+(2*1)+(1*4)=143 143 % 10 = 3 So 118684-14-3 is a valid CAS Registry Number.