The CAS Registry Mumber 1450711-55-3 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,4,5,0,7,1 and 1 respectively; the second part has 2 digits, 5 and 5 respectively. Calculate Digit Verification of CAS Registry Number 1450711-55: (9*1)+(8*4)+(7*5)+(6*0)+(5*7)+(4*1)+(3*1)+(2*5)+(1*5)=133 133 % 10 = 3 So 1450711-55-3 is a valid CAS Registry Number.