The CAS Registry Mumber 113859-94-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,3,8,5 and 9 respectively; the second part has 2 digits, 9 and 4 respectively. Calculate Digit Verification of CAS Registry Number 113859-94: (8*1)+(7*1)+(6*3)+(5*8)+(4*5)+(3*9)+(2*9)+(1*4)=142 142 % 10 = 2 So 113859-94-2 is a valid CAS Registry Number.