The CAS Registry Mumber 89495-68-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,9,4,9 and 5 respectively; the second part has 2 digits, 6 and 8 respectively. Calculate Digit Verification of CAS Registry Number 89495-68: (7*8)+(6*9)+(5*4)+(4*9)+(3*5)+(2*6)+(1*8)=201 201 % 10 = 1 So 89495-68-1 is a valid CAS Registry Number.