The CAS Registry Mumber 54595-71-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,4,5,9 and 5 respectively; the second part has 2 digits, 7 and 1 respectively. Calculate Digit Verification of CAS Registry Number 54595-71: (7*5)+(6*4)+(5*5)+(4*9)+(3*5)+(2*7)+(1*1)=150 150 % 10 = 0 So 54595-71-0 is a valid CAS Registry Number.