The CAS Registry Mumber 52618-00-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,2,6,1 and 8 respectively; the second part has 2 digits, 0 and 0 respectively. Calculate Digit Verification of CAS Registry Number 52618-00: (7*5)+(6*2)+(5*6)+(4*1)+(3*8)+(2*0)+(1*0)=105 105 % 10 = 5 So 52618-00-5 is a valid CAS Registry Number.