The CAS Registry Mumber 132680-63-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,2,6,8 and 0 respectively; the second part has 2 digits, 6 and 3 respectively. Calculate Digit Verification of CAS Registry Number 132680-63: (8*1)+(7*3)+(6*2)+(5*6)+(4*8)+(3*0)+(2*6)+(1*3)=118 118 % 10 = 8 So 132680-63-8 is a valid CAS Registry Number.