The CAS Registry Mumber 889-35-0 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 8,8 and 9 respectively; the second part has 2 digits, 3 and 5 respectively. Calculate Digit Verification of CAS Registry Number 889-35: (5*8)+(4*8)+(3*9)+(2*3)+(1*5)=110 110 % 10 = 0 So 889-35-0 is a valid CAS Registry Number.