The CAS Registry Mumber 26832-97-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,6,8,3 and 2 respectively; the second part has 2 digits, 9 and 7 respectively. Calculate Digit Verification of CAS Registry Number 26832-97: (7*2)+(6*6)+(5*8)+(4*3)+(3*2)+(2*9)+(1*7)=133 133 % 10 = 3 So 26832-97-3 is a valid CAS Registry Number.