The CAS Registry Mumber 131967-49-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,1,9,6 and 7 respectively; the second part has 2 digits, 4 and 9 respectively. Calculate Digit Verification of CAS Registry Number 131967-49: (8*1)+(7*3)+(6*1)+(5*9)+(4*6)+(3*7)+(2*4)+(1*9)=142 142 % 10 = 2 So 131967-49-2 is a valid CAS Registry Number.