The CAS Registry Mumber 1965-76-0 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,9,6 and 5 respectively; the second part has 2 digits, 7 and 6 respectively. Calculate Digit Verification of CAS Registry Number 1965-76: (6*1)+(5*9)+(4*6)+(3*5)+(2*7)+(1*6)=110 110 % 10 = 0 So 1965-76-0 is a valid CAS Registry Number.