The CAS Registry Mumber 75177-65-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,5,1,7 and 7 respectively; the second part has 2 digits, 6 and 5 respectively. Calculate Digit Verification of CAS Registry Number 75177-65: (7*7)+(6*5)+(5*1)+(4*7)+(3*7)+(2*6)+(1*5)=150 150 % 10 = 0 So 75177-65-0 is a valid CAS Registry Number.