The CAS Registry Mumber 132274-55-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,2,2,7 and 4 respectively; the second part has 2 digits, 5 and 5 respectively. Calculate Digit Verification of CAS Registry Number 132274-55: (8*1)+(7*3)+(6*2)+(5*2)+(4*7)+(3*4)+(2*5)+(1*5)=106 106 % 10 = 6 So 132274-55-6 is a valid CAS Registry Number.