The CAS Registry Mumber 42495-96-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 4,2,4,9 and 5 respectively; the second part has 2 digits, 9 and 6 respectively. Calculate Digit Verification of CAS Registry Number 42495-96: (7*4)+(6*2)+(5*4)+(4*9)+(3*5)+(2*9)+(1*6)=135 135 % 10 = 5 So 42495-96-5 is a valid CAS Registry Number.