The CAS Registry Mumber 91324-49-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,1,3,2 and 4 respectively; the second part has 2 digits, 4 and 9 respectively. Calculate Digit Verification of CAS Registry Number 91324-49: (7*9)+(6*1)+(5*3)+(4*2)+(3*4)+(2*4)+(1*9)=121 121 % 10 = 1 So 91324-49-1 is a valid CAS Registry Number.