The CAS Registry Mumber 89986-00-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,9,9,8 and 6 respectively; the second part has 2 digits, 0 and 0 respectively. Calculate Digit Verification of CAS Registry Number 89986-00: (7*8)+(6*9)+(5*9)+(4*8)+(3*6)+(2*0)+(1*0)=205 205 % 10 = 5 So 89986-00-5 is a valid CAS Registry Number.