The CAS Registry Mumber 132621-49-9 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,2,6,2 and 1 respectively; the second part has 2 digits, 4 and 9 respectively. Calculate Digit Verification of CAS Registry Number 132621-49: (8*1)+(7*3)+(6*2)+(5*6)+(4*2)+(3*1)+(2*4)+(1*9)=99 99 % 10 = 9 So 132621-49-9 is a valid CAS Registry Number.