The CAS Registry Mumber 113967-11-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,3,9,6 and 7 respectively; the second part has 2 digits, 1 and 1 respectively. Calculate Digit Verification of CAS Registry Number 113967-11: (8*1)+(7*1)+(6*3)+(5*9)+(4*6)+(3*7)+(2*1)+(1*1)=126 126 % 10 = 6 So 113967-11-6 is a valid CAS Registry Number.