The CAS Registry Mumber 143332-43-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,3,3,3 and 2 respectively; the second part has 2 digits, 4 and 3 respectively. Calculate Digit Verification of CAS Registry Number 143332-43: (8*1)+(7*4)+(6*3)+(5*3)+(4*3)+(3*2)+(2*4)+(1*3)=98 98 % 10 = 8 So 143332-43-8 is a valid CAS Registry Number.