The CAS Registry Mumber 89488-54-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,9,4,8 and 8 respectively; the second part has 2 digits, 5 and 4 respectively. Calculate Digit Verification of CAS Registry Number 89488-54: (7*8)+(6*9)+(5*4)+(4*8)+(3*8)+(2*5)+(1*4)=200 200 % 10 = 0 So 89488-54-0 is a valid CAS Registry Number.