The CAS Registry Mumber 132210-34-5 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,2,2,1 and 0 respectively; the second part has 2 digits, 3 and 4 respectively. Calculate Digit Verification of CAS Registry Number 132210-34: (8*1)+(7*3)+(6*2)+(5*2)+(4*1)+(3*0)+(2*3)+(1*4)=65 65 % 10 = 5 So 132210-34-5 is a valid CAS Registry Number.